I would suggest you let your husband go back to UK on his own and when established financially , apply for your spouse visa..it would be harder for him to look after a child and find a job at the same time..so let your daughter stay with you.

btw, why didnt you apply for ILE? you and your husband lived together for 5years and if your mother in law can provide accommodation with enough supporting documents like mortgage papers,sponsors letter etc..you have a good chance to be granted a visa.