Most of the Mountain Meadow victims were baptized Christian (not Mormon) at the time of the massacre. It was only over a century after the massacre that these victims were “proxy baptized” in the Mormon sect by descendants of the original perpetrators. This act was protested by descendants of the Christian victims, as you can read here:
http://1857massacre.com/MMM/lds_proxy_baptism_of_massacre_victims.htm
But since their Mormon religion is a complete hoax, who really cares what these proxy baptisms mean. I mean, they could declare all of the victims to be popes, and it wouldn't make a difference. Mormonism is a fraud.