If it's any help Lisa, I found in my experience that allowing my bladder to fill more than half way also made the contractions really strengthen up. Keeping my bladder on the empty side was better. But she does still need to keep her fluids up, and if she has a drip up, she will be finding her bladder filling frequently. So she needs to keep a bedpan handy, and use it freely. Don't wait, don't fret about being a problem for the staff.
If she is permitted, it will be less physically strenuous to use the bedpan out of bed sitting on a chair, if they will let her. Walking to the toilet probably is not permitted right now.
I had about six months of this with difficult child 3, four months of it with easy child 2/difficult child 2, same with difficult child 1 (much stronger contractions - I was avoiding moving therefore avoiding the toilet unless busting - this is how I learned that more frequent visits is better, even though it requires more movement) and three months of it with easy child.
The other thing - if it's salbutamol they have her on, it will be sending her heart rate way up. She will feel shaky and maybe dizzy. I remember my resting heart rate was in the 90s and higher. With difficult child 3 I was on double dose and I was also badly anaemic. It really can knock you around. But as soon as you can stop the pills, it improves.
Marg