If you have a package deal at the hotels, parking is included. If you have room only, then you're charged $7 for parking, daily newspaper .... If you're not staying at the hotel, you'll be directed to the Downtown Disney parking or the Mickey & Friends parking structure.
There is handicapped parking at the structure that is considerably closer to the trams. If you must go on the upper levels (I don't know if they'll just keep you on the first level, or if you'll go to an upper level, there are elevators to take you down. The parking structure is 6 stories high & as big as 4 football fields -- pretty big.
It seems to me that it would be shorter for your daughter if you use the hotel shuttle. The distance to the shuttle drop offs and the trams to the parking structure are about the same. From the tram, you then need to get to your car. At the shuttle drop off, you just get on, and then you're dropped off near your hotel.
Do you know if the hotel has its own shuttle, or if you'll be using the Anaheim Resort Transportation (ART)? Keep in mind that if you're using ART, you'll be charged $2/day, or $5/for entire stay per adult if you include that in your package when you book (at least, Dreams Unlimited Travel will get one for you when you book if you need it).