I honestly hate to come to any of their defense (because I don't think anyone in the family warrants it most of the time), but a lot of Christian faiths that observe Holy Thursday and normally have/attend a service for Holy Thursday are doing something in substitute for the normal "foot-washing" portion of the service which is typically there more to help illustrate what the day was about than anything else. My dad is a priest in a Christian religion and had asked his congregation to prepare some bowls and towels at home if they wanted to participate in that part of the service while he was livestreaming it.
So, I guess what I'm saying is that this is one of the less weird things I see on her Instagram lol