My mom is travelling from Manila to PEK with CA and has connecting flight to Chicago thru UA

When she checks in her luggage in MNL, will she need to claim this in PEK then check it in again with UA or will she just have to claim checked luggage at her final destination?
Also, I asked for wheelchair for ramp assist for her. Does this mean they will help her from gate to gate? Will she be identified by the stewardess as such thru the boarding pass or she has to approach attendant to get help?