Around here the Matron or Maid of Honor, and bridesmaids normally pay for the Bridal Shower, My Daughter got married a year in a half ago, Her MoH and the other bridesmaid had her shower at the MoH moms house. The MoH called and asked me if I would make a watermelon basket for the shower, which the answer was of course, and I footed the bill for it.
I have been to a several showers given by the brides mother or grooms mother. I really did not think anything about it.