AITA for showering during the day?

Throwaway because my regular account is the username I use for everything, obligatory I'm on mobile, character limit, etc.

First, to give you a little background. I (F29) moved into my new place just prior to you know what. I rent the upper level of a home with my husband (M33) and we absolutely love it here. To give you an idea of the layout, it's an old house in a very old New England town, our home is very close to the neighbors. A small alleyway separates our houses, maybe 8 feet wide at most. There are a lot of windows in each house, and these windows face each other mostly at eye level. I have not met my neighbors due to current world events. Anyway, onto the story:

Everyday I have a routine. I wake up early, work out for a couple of hours, then take a shower. Today after getting out of the shower, my neighbor surprised me by ringing our doorbell. She's a mother of two (M8 and M14) and came by to inform me she caught them spying on me while I was in the shower. We have an opaque window cling covering the bottom portion of the bathroom window that was here when we moved in. My husband and I didn't worry about the top half because again we live on the upper level, someone would have to be in an attic staring down into the window to see anything, and the top half gets steamy anyway. Well, her sons have apparently been doing just that... going up into the attic to look down into our bathroom while I shower. She said has caught them doing this several times since we moved in. I was horrified and thanked her for telling me, and asked her how she planned to discuss this with her sons.

Wrong move, she. Blew. UP. Let me be clear, I don't parade around my house naked. I don't press my breasts against the window and shake 'em around while I shower, I just exist like a normal person within my home. I genuinely did not realize I could be seen. She started berating me for corrupting her sons, and insisted I begin showering at night with the light off to ensure they would no longer be 'tempted' by me. I was in shock and told her I would absolutely not be doing that, it's a safety hazard and besides it doesn't address the real problem- her young boys being peeping Toms.

She was screaming at me on the porch at this point and I told her to get away from me before closing my door on her. I'm infuriated she's making me out to be some kind of predator, when it was my privacy that was violated. I ordered a window cling for the top half that should arrive in a couple of days but I'm still humiliated and angry. I have absolutely no plans of waiting all day covered in sweat after exercising to shower at night in the pitch dark. My husband is pissed at the neighbor, but my sister (who also has a young son) agreed with her and kind of tore into me. She said if I had kids I would understand. I'm genuinely conflicted. I don't want to rearrange my entire day for these little pervs. Am I the asshole for this?

EDIT: When he got home from work my husband and I sat and read all of these comments, thank you everyone for your input. A lot of you made some very good points I hadn't really been thinking about with regards to the boys behavior. To answer a couple of questions:

1. To be more clear, the window is 3ft tall by 1 foot wide. We have a tub with a showerhead, the window is built into the outside wall of the building shared with the shower, if that makes sense. So yes you are standing in front of a window while you shower. The uncovered top half of the window begins just below my collarbones; if the neighbors' window was eye level, the boys would only be able to see my face and head. However they are going upstairs and looking down into the shower from above; I hope this paints a clearer picture.

2. We had only met the previous tenants during the walkthrough, a man and a woman in their 20s. I have no idea if the boys watched them, but after speaking to both my landlord and the downstairs neighbor about it, as far as they know the previous tenants had no problems with this neighbor. Both downstairs and our landlord confirmed they have not had previous issues with this neighbor either. They are a wealthy family that owns the home.

3. While I can appreciate cynicism, I feel many of the people messaging and commenting as though I am playing dumb for karma because how could I possibly think I'm the asshole? Did not read through. I don't necessarily think I'm an asshole for the act of showering in general; I was debating on whether I was an asshole for not thinking the window cling through and showering in the daylight without it. After speaking to my sister on the phone and arguing, she made me feel like an asshole as she acted like it is common sense to have covered the whole window as soon as we moved in. I really never thought of that, neither did my husband. It was like this when we moved in so we assumed it was OK. I also worry my question, though not intended to be rude, was an overstep to my neighbor as a parent due to her reaction. I was fully going into this expecting a torrential downpour of YTAs (hence using a throwaway rather than be traced back to my real name and face). Sorry about the title, I was still pissed when I wrote this, it is what it is. But you can read the post.

For now we have taped up a garbage bag in the window as many of you suggested. The window cling I ordered should be here Monday. I don't know if I want to contact the police. We just moved here and don't want to cause trouble. My landlord has known these people for years and is friendly with them, she offered to talk to the mother ONLY if the mother reached out to them to complain about the situation. If not, we're going to leave it be for now and hope that's the end of it.

PS my husband and I both cackled at all the comments calling my sister an idiot; we've butted heads in the past and I love her to death but she is quite bossy, holier than thou... I almost want to send her the link just so she can see another perspective.

Thank you all for your comments and suggestions, truly.