With the approval of church elders in our previous church, I baptized several ladies I had been discipling. My husband baptized a husband, and that newly-baptized husband baptized his wife. In our current church, the Children's Ministry leader (female) baptizes her age group, as does the middle and high school pastors (male). A believer may baptize their own family members if they request to do so. Our baptistry is large enough that entire families are baptized while in the water together. I've seen parents of handicapped children go under the water with their child to assist the one baptizing them. I've seen a woman help her husband who had serious back problems assist the one baptizing him by supporting his upper body as he went down and came up.
I'd post some videos, but the music in the background might offend some weaker brothers here.
It's all good.