My daughter is also tall and has been hunting in a tree stand with me the last 4-5 years. She wore a Hunter Safety System® Lil' Treestalker vest, till this year. She is now 11 years old and tall enough that there is no longer enough leg strap to let out, so this year I purchased her a new HSS ladies pro vest size small and it works great. I liked it so much I bought a HSS pro vest for myself to replace my aging SOP harness.
I think the HSS one would be a great choice! We have been very impressed with all their products.