"Planning" age gap??

[SarahH12]

Hi, DP and I are discussing ttc in the next few years. We have DSD who's 6. Ideally we want to have a minimum gap such that DSD is in secondary school when baby DC starts primary school so that we're not trying to drop off at two different primary schools that are miles away.

Can anyone help me figure out dates please as I'm getting confused! When is the earliest we can start ttc? I know it could take months or years but ideally the gap we're looking at is a minimum rather than a maximum iyswim.

I think 2 years at the earliest?
You may know this already but if you have one child in a primary school the their siblings get priority in placements. Obviously if it's a tiny village school then children from that village are first priority the siblings are second etc, but generally they try and keep siblings together for this reason.

@lapenguin problem is DSD is in primary school where her Mum lives whereas we live 20 miles away - hence not being able to drop both off if they're both in primary school.