My Ex has offered me �50 a week child support for my 3 girls?

It doesn't sound right to me and I have no idea of costs where you live. He should be paying half of the cost of feeding, clothing, housing and schooling the girls, since he is half responsible. If he is talking to his solicitor, then you should also be talking to yours. If you don't have one, then get one because, like all separations, this could get dirty.