Help! Salary decrease & childcare?

I’m looking for advice from anyone that has asked for a salary decrease to help qualify for certain government help? 😬 I am returning to work full time but my partner is a mature student so we don’t qualify for the 15 free childcare hours but we do get money through student finance to subsidise this instead (which actually works out more beneficial anyway). However, when I return to work my pay has increased ever so slightly which takes us £4(!!!!) over the threshold to receive this money from SF but equally we still wouldn’t get any free hours so are left with ZERO help. 😭 Can I legally ask my employer to decrease my pay for this reason? Or would I also have to cut more hours to reflect the pay? I have already cut down to 4 days for this reason but have still just missed out on the threshold for help. Without the free hours, we literally cannot afford to put our baby into nursery as there is just no help for couples where one is a full time student and one works full time!!! It’s just infuriating that we would get more help if we both worked 16 hours and claimed benefits than a hard working couple who are doing everything we can to have a good life for ourselves! 🙃