Expecting the gift back is very, very childish. This couple had to downscale their wedding, likely lost a deposit or two, and probably had to cancel their honeymoon (or at least modify it a lot). I'd be more inclined to send them a little something extra than ask for the gift back. My thinking is, "They've been through so much."
If the couple has a reception or large gathering to celebrate the wedding later, the LW and her mother wouldn't need to gift for that occasion.
I can't believe, in the middle of a global pandemic, that the LW can't have a little empathy for this couple.