There are many things that can affect incontinence, because there are different types of incontinence.
I don't know if it is possible right now due to the pandemic, but really, what I would suggest is that she see her provider to determine the kind of incontinence she has and to discuss her options. Some examples:
-Stress incontinence (when urine comes out as a result of movement, coughing, sneezing, etc.; this is very common in women and may occur due to obesity and childbirth)
-Urge incontinence (a sudden uncontrollable urge to urinate; this is most commonly managed with medication)
-Overflow incontinence (the bladder does not empty fully and the result is urine loss; this may be managed with medication changes and bladder training)
-Functional incontinence (this isn't due to a bladder problem directly; it occurs when a person has difficulty with activities such as getting to the bathroom, getting clothes off, etc.)
-Mixed incontinence (two or more issues)
A provider can help to determine the potential type of incontinence she has, and can also review her medications to see if they are contributing - some do. It's possible that there may be an incontinence clinic or service to which she can be referred.
Grannynannywanny is quite correct. It's very important to drink enough water, especially if your mother is on some types of medications. Not only can too little water affect the kidneys, it can cause dehydration, which can increase her risk for falls and delirium.