I personally believe at least 3 days in the park should be necessary. However, the fact you have kid and parents with you will limite your reach to some the most beautiful spots in the park. You will still enjoy a lot, such a short walk to the foot of Yosemite Fall, viewing whole valley from Glacier Point, et al.
Agreed with above two posts about lodging. Wish there is still some available. Usually you have to reserve couple of months ago for a relative good room. Otherwise you have to camp. You have to be ready to make change of your visit in the park if lodging is not there.
Driving is another important issue. Try to avoid driving as much as possible after dark. It is really challenging, even in day time. And it will take much longer time than you expect from point A to B, especially in crowed summer season.
Agreed with above two posts about lodging. Wish there is still some available. Usually you have to reserve couple of months ago for a relative good room. Otherwise you have to camp. You have to be ready to make change of your visit in the park if lodging is not there.
Driving is another important issue. Try to avoid driving as much as possible after dark. It is really challenging, even in day time. And it will take much longer time than you expect from point A to B, especially in crowed summer season.