I think you're about as well prepared as any parent could be, and probably better than most. You're seriously thinking about it, and taking advance steps such as the swimming lessons.

I think you and Sharon will do just fine.

Oh and re this bit:

Can't be prepared for any of the twists and surprises (Lex, why did you set fire to Parliament?), or the nasty shocks (You want to be a chartered accountant?) but I'm looking forward to the adventure.

The former might be a problem but can't really see the latter happening. :)