Mostly, I know exercise will go by the wayside, but I sneak in whatever workouts I can. When people are able to visit, I always ask them if they'll stay with my daughter long enough for me to take a shower or, better, to take a walk or go for a run. When we can't have visitors, I time my showers or coffee runs to coincide with the arrival of a Child Life specialist or another volunteer-led activity, like a visit from a princess, a support dog, or the art or music therapy folks. I have done yoga in the room when I had space and we weren't sharing it. If I need a minute, I'll bring my kid down to the playroom to color or play with the kitchen set so I can sit and read or scroll through social media for a half hour.
At the very least, I can keep myself from falling apart completely by packing an ample toiletry bag including my own toilet paper, a toothbrush and toothpaste, my own soap or shower gel and lots of lotion, all my medications (including Tylenol for headaches), any sleep aids, earplugs, and a neck pillow. And I do not hesitate to ask for help. If she needs anything, I ask. And if I need anything, I ask.