It feels like walking with a shopping cart. They usually have a seat attached. It is right for some people but not for everyone. Depends on how much help/support you need for walking.
If you search any search engine you can see how they look when using and you will probably know if you think it would be right for you, after seeing what your doctor has to say.

First you must ckeck with your mother's Physical Therapist and MS to see if this would be beneficial for her needs. The Rollator helps to offer stability and balance to the user so they don't need to worry about staying upright or supported. This device offers independent mobility those suffering from injury, knee problems, joint problems, etc.

A Rollator is an upright walker for elderly people, or anyone who may need one. Your mother’s Dr. or physical therapist could recommend if one would be good for her.

Much needed
I constantly am using the seat to sit on!
Save my energy
Essential in my life
As well as my scooter !

I have two versions of a rollator. Both have brakes which is nice when you feel your brain is working faster than your body. I use one around the house when I'm trying to clean since it has a seat.
I have another one that looks very similar but it comes with legs for a wheelchair. This one I keep in my trunk in case I go somewhere and start to feel tired, at least I can use it as a wheelchair if needed.