Hi everyone, I have a question regarding keeping horses out when it's raining. So we have a 10 acre property split into 3 fields. The front and back pastures have access to shelters with a roof and sides. The front, middle, and back also all have tree coverage. The only pasture without a shelter is our middle pasture.

We had flooding last week, and the debris caused some damage to the fencing in our front pasture, which is going to be fixed tomorrow, but as of right now, we are not using the front pasture.

There's 4 horses, 2 geldings (one of the geldings is actually my husband's grandmothers), and two mares. One of my mares is in heat, so the geldings are in our back pasture with each other, while the two mares hang out in the middle together. It started to rain while they were outside for the day. The geldings had access to the barn while the mares had trees they could go under. The problem is, at what point should the horses be put away in their stalls? I was visiting my mom an hour away yesterday but was watching the weather on my phone all day. My husband's grandma texted at noon that she was putting all the horses away. I figured there had to be severe weather, but when I checked it didn't seem like anything crazy? It seemed like there was some thunder but our horses couldn't care less about thunder. She kept the horses locked up for the rest of the day which I do not agree with. I also asked her to at least give them hay and it looks like she gave them scraps. I'm just feeling frustrated and unsure if maybe I'm wrong and I should take the weather more seriously? What do yall follow? I read a page on Texas A&M's website and felt it seemed to say it was okay to let them stay out?

Edit: I live close to Houston, Texas if that helps when answering.