I'm disabled and have status on Skyteam. However, I fly plenty on airlines where I have no status. Follow other advice given - no "last flights out" on your connection. Get Skycap to help shuttle your luggage about - its worth a few $ in tips. Make sure you check in at COUNTER, and make sure they know of your special needs. They will offer pre-boarding for those who need it - your entire party qualifies. Board early, take your time, get your stuff stowed. Make sure the FA knows of any special needs you have. Most of all, be polite and friendly, and they will help you. They will be very relieved to find a disabled PAX accompanied by caring relatives - much less worry for them. Plan ahead if needed and request in-airport transport on carts, or a pusher for a wheelchair. Even if you can push your child you will have had a very long day and could use the help. Remind the FA before landing, politely, of and needs you have on ground.

Take special care if you happen to be flying ASA connecting in ATL. I have seen them treat mobility-challenged PAX poorly, mostly through ignorance instead of malice.

Enjoy and appreciate any special treatment, and do not worry about lack of status. You'll be fine. Please let us know how things go.