How is it permissible to perform ablution by wiping over socks if they were put on without being in a state of ritual purity, due to a medical necessity that prevents their removal after being worn without ritual purity?

Wiping over the socks is not permissible if they were not put on after a complete state of purity. What you mentioned about the importance of wearing them before getting out of bed does not justify wiping over them in that condition. A woman can move and perform ablution, then extend her legs a little, and then put on the socks. So, it is not permissible to wipe over them if they were put on while not in a state of purity.