She deserves her own happy ending, and her fling with Rick really helped her to understand that for herself.
Although Kirsten was a straight shooter and often a hardass in Set It Up, she was also shown to be a caring and honest human being.
If Harper and Charlie can somehow be written into the plot, as well, I’m all for it.
When last we left Kirsten–and SPOILERS OBVIOUSLY– she decided to leave Charlie’s boss Rick after both Harper and Charlie told her that Rick really didn’t want to be with her and was using her as a means to make his ex jealous.