Hello Delayne, I'm Dr. Deb and will do my best to help you today.
I can understand your concern that Sage hasn't urinated yet but hope to reassure you that this isn't something that you need to be overly concerned about at this point. I'm always amazed at the sphincter control which some patients appear to have and if she's experiencing ataxia and is also a shy urinator, then there are several explanations as to why she hasn't urinated.
The best thing you can do is to encourage fluid intake since what goes in must eventually come out. I'd offer her low sodium chicken broth or tuna/clam juice which may be more palatable than plain water. Because these products do contain more sodium (but not enough to cause harm), she may tend to drink more which result in more urine production.
If you're not already doing so, it may also be helpful to support her with a towel around her midsection. She may not necessarily want to urinate in front of you, but when her bladder is distended enough, she will.
Compression of her bladder isn't likely to be effective although you can apply gentle pressure to her abdomen in between her legs if you want to try.
More than likely, she'll urinate in the next few hours either consciously or while she's laying down. Therefore, it may be prudent to place a towel near her vaginal area.
I hope this helps to reassure you about her. Deb