currently our family has 3 dogs: let's call them old girl (~14yo), fluffbutt (3yo) & puppy (4-5mo). we took in fluffbutt when she was about a year old and she would sometimes try to play with old girl who was having none of it, and fluffbutt usually took it in stride & found some other way to entertain herself. but we felt bad for her and decided to get another puppy, especially since we had to say goodbye to old girl's mom last year. puppy & fluffbutt play great together, problem is puppy also tries to play with old girl, who is still having none of it, but puppy is a lot more... insistent about it and not only gets overly nippy but causes fights when fluffbutt doesn't know whether to protect old girl or defend puppy.

i want to give old girl someplace where she can hide from puppy but still allows her freedom of movement when she wants food/water or needs the bathroom. can anyone recommend something that's easy for an elderly small breed to get in/out of but also ensures puppy will respect her space & leave her alone?