If the walker collapses, it will fit on the Canadair 700 and Embraer 135, 140 and 145 regional jets. The problem can sometimes be the flight attendants, who don't think it will fit. It has to be collapsed and then turned upside down (wheels up) to fit in the closet.

If she can use the walker, she can probably make her way down the aisle. Ask the gate agent for a seat towards the front...or if she may need the use of it, it could be advantageous to sit close to the lavatory.

I am appalled at the lack of sensitivity of some of the folks that help our passengers with an aisle chair. It is as if they are moving a big, cumbersome bag, devoid of feelings. I'd avoid that for my family member, unless it was absolutely necessary.