To be honest, there is no good timeline for that as we all have different requirements and commitments in life. For example, a year for me might be too long or short for you. They are also some children who need longer time to adapt to new environment. My firstborn took 1 week to blend in to school but my second child has been in school for 3 months still not coping well.
When I first quit my job to stay at home with kids, I plan to do so until my child is one year old. However, she is not coping well in school too so after much discussion with my husband we decided to postpone all our plans and let me continue to stay home to take care of them to nurse them back to health. To us, car, house, vacation can be earn be much later or slowly (doing part time job at home now) but children's health, childhood etc can't be reveresed and once you missed you only have regrets but there is always newer car, house when we are financially ready.
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