Child Tax Credits payment received via GIRO

My wife and I jointly made a new claim for CTC and received four Giro cheques all under my wife's name who is on a 2 yr spouse visa.

As she is the main carer of the child as I am working full time is this the reason why they have made the cheque payments to her and not me ? Would it be better to have the main carer's details changed to mine?

We did provide joint bank account details and are totally clueless why we have received payments in this method. The last we want to do is cash the cheques at the bank and post office and later to find out she has claimed something under her name. I'm trying best to keep everything under my name.