death

she wants to see that guy at her sister's funera againl

to find her true love again

she found that her sister was dating this guy, she killed her for jealousy

This guy was either her sister's boy friend or fiancee or husband she did not know about earlier.

After killing her sister she could get rid of her love ( of course sickening) and then she could meet him again at her funeral.

This guy was the priest???? Which would answer why she didnt need his number as she knew he would be at her sisters funeral????

she was probably being a bitch.

she wants another funeral to find him

She thinks that after killing her sister there will be another funeral, by that she thinks she will meet him again.

This is an old classic and you've gotten a few pieces and spin off's, but they've all been portrayed inseries shorts, originally in "Night Gallery" or "sequeled "Tales from the Crypt" or other mystery type venues(not sure of exact one). The original story was that she believed he was at first funeral due to closeness of blood or family friendship. If her mother's other daughter died, he'd likely return for the second funeral. She awaits with the grieving, anticipating identifying her llove and bringing it to fruition, only to find he
was a priest, not performing the service, but there as friend.(some have him performing the second funeral service, others have the priest greeting him afterwards, identifying him. Thus she is ironically crushed to never see her love fulfilled.
Weird /funny ones have him being gay, there with his lover at second funeral. Still others have him the unseen new boyfriend, betrothed of eloped husband of the sister who kept up the relationship secrecy at the funeral because they planned to make the big announcement later, and the women then finds a picture of her sister with him(married-eloped) at her sisters home before the funeral, or thru the grieving groom and friends with pictures remarking of the tragedy of his true love's fate. Some reverse it with brothers.
Either way, it's like "Texas Cheerleader Mom" croossed with "Harold and Maude" with a touch of 'Timmy' from the puppet TV Dinosaur series(the one that parallels the Flintstones, with the baby always saying-"Not the Mama, not the Mama" to his dad and watching their tv version of 'Mr.Science' where lab tech Timmy was always getting blown up/burned etc and everyone says"uh oh, we're gonna need another Timmy" and "Wow, again, again")
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A better twist would be, with her love so strong, to have her kill "his"sister and ask why?

It ends up he was her brother given away in adoption or divorce or separation of some kind before she new him or was born, and the mother never spoke of him. Both were sole children of their households growing up! And she was really in love.