No, because if our birth rate drops, we are told we need more immigration, regardless of the health and skill level. It's much better for a country to have a stable birth rate, than ship hundreds of thousands of adults within a fifteen year age range.
The OP's family costs the same as, one year, per person, in prison. We put people in prison who we could deport. That's before stupid spending, tax breaks and overseas contributions (not aid). Part of the reason we don't have communities etc is because we've stopped valuing families. The OP is bringing up seven children, the eldest is off to university, the OP is in further education, so she is teaching her children, education matters. She's cost less than one child going through foster care, or what Preston Davey's family has caused/cost. Were does putting a price tag on start? Why are we attacking the people needing a bit of help, but doing a good enough job?
@Tings my children were partly raised on benefits. I've been praised, the last time was in the dental hospital with my youngest when she was 26. So I wouldn't put money on your theory. FYI all my children are in work.