I have a memory of reading a short story maybe by Ann Rinaldi, Mercedes Lackey, Robin McKinley, or Marion Zimmer Bradley about a girl who goes into a rose garden and every time she touches a rose, different storylines for her life appear.
It is the short story "Roses by Moonlight" from the collection Book of Enchantments by Patricia C. Wrede, published in 1996.
A young woman named Adrian is bitter and jealous of her younger sister, Sam's, success, popularity, and looks. While avoiding Sam's party, she meets a woman who takes her to a garden of roses. Each rose contains a possible future for Adrian, success in work, love, failure, death, or continued bitterness against her sister. She finds one flower, only a bud, that shows her and Sam agreeing to work harder to get along. She is told she may pick just one flower, but she decides to forego the garden, and chose her own future. The woman and her garden vanish, and Adrian, still not wanting to go back to Sam's party, decides that there will always be time to talk to Sam tomorrow.
It tells the story of a girl, Adrian, who is jealous of her younger sister, Sam. From Adrian’s perspective, Sam has everything—friends, looks, and success.
While ignoring a party that Sam is having, Adrian meets a strange woman who brings her to a garden of roses. Adrian is enthralled by the beauty of the roses, and goes to pick one. The woman stops her with the warning to choose one and be careful about which she chooses. Adrian quickly learns that each rose contains a potential future. She travels the garden, sniffing roses, and being treated to every possible future she could have from riches to dying of cancer. None of the roses, though, offer what she is looking for.
Finally, she sees a rose that seems to be struggling. Unlike all of the other roses in the garden, this one is disheveled and barely in bloom. When Adrian sniffs it, she is treated to a scene between her and Sam talking and apologizing to one another for how they treated each other over the years. The woman appears at Adrian’s side and asks if that is the rose Adrian wants. Adrian thanks the woman but declines her offer to choose a rose. She leaves the garden understanding what the future can bring and resolving to make it her own.