You must answer with the truth, but what you've shared is not an issue
Your husband is fully entitled to claim child benefit.....no problems.

Working tax credits and child tax credits must be claimed jointly as a couple....but again this will not present any issues.

Here's what UKVI state :-

A person subject to immigration control is not considered as accessing public funds if it is their partner who is receiving the funds they are entitled to.
Child and working tax credits are claimed jointly by couples. If only one member of a couple is subject to immigration control, then for tax credits purposes, neither are treated as being subject to immigration control.