Good luck Katedan.
My partner had a Ross Procedure in his early thirties - if you don't know what that is, its taking both valves out, chucking the one from the high pressure side away and putting the one from the low pressure side in its place and then replacing that one with a porcine valve. He had his first ops as a baby, followed by heart bypass at 13. Have to say though, it took him until well after the Ross to accept his body, so I empathise with what you say about feeling too young. Once he accepted it, he started to live life in spite of his heart, and not because of it.
A couple of months ago, his mum had her valve repaired - she is in her 60's.
Obviously, the repair takes a lot less time than the replacement so that is a great start. DPs mum took about 8 weeks to fully recover - in the meantime, she just took things very slowly. Bear in mind she is in her 60's too, and as someone has already pointed out age is most definitely on your side!
So... whilst not having first hand knowledge, I have seen it first hand, so the best advice I can give you is make arrangements for childcare -you will need plenty of rest as you will be tired afterwards. You will also not be able to lift anything, and that most definitely includes a 2 year old!
Have you got that level of support around you? - also, put in a claim for attendance allowance? I'm not entirely sure of the rules on claiming, but if you are eligible, it may help with childcare costs. The Dept for Work and Pensions will be able to tell you.
Let us know how you get on