If the woman is not disabled, please do not request a wheelchair due to other concerns. That is inappropriate use of limited resources. If she cannot stand or walk for long periods, then go ahead and make the request. Do NOT expect them to play translator for her, it's possible the chair pusher won't even be able to read much less comprehend much english. That is not a job requirement. (wheelchair pushers expect to be tipped, make sure she has something to hand over and they might be a little nicer - or not)

If you are really concerned, and she is likely to get lost or have issues, then consider booking a second ticket for someone to accompany her.

Defnitely provide her notes to hold onto and hand over if she needs something. Give her cheat sheets as far as the simple, where is the bathroom, can you direct me to the gate for X flight, my name is Y and I only speak Z, etc. Walk her through the process multiple times so she knows what to expect. How to board a flight, how immigration versus customs works.