I have taken my DD three times to WDW on my own and we had the best time ever. You dont have to constantly please other people all the time the two of you just have great fun together.
We stayed at ASMo and I did not hire a car.
Last easter when we went my DD said that she felt that her heart had been ripped out when it was time to leave after 14 days. She is 10 yrs old ane we could easily have stayed longer.
Its a great bonding time for both of us as at home we do tend to clash a bit, with her being a pre teen and as my DH only has 4 weeks holiday and we go other places in those weeks, I find that Disney is by far our favourite place.