Who to give me away with no parents or siblings

My mom , dad all my grandparents have passed away. My brother i dont speak to for over 20 yrs. I have 3 girls and a son who passed away. Had he been alive he was the one who would have when or if i got married.

I dont know what to do . How would i encorporate 3 girls walking me down they are 21, 18 and 15 ? Or do i walk alone ? Wedding is a year away but its on my mind