My name is Sucia!

Sucia, Suci for short (pronounced "Sue-C-ah", but she is open to being renamed).
We rescued her from the Wind River Reservation in Wyoming almost 10 years ago. She walks well on a leash and has good recall. She loves to play frisbee or fetch sticks in shallow water. She got along well with our older dog and gets on with some other dogs once she gets to know them, but can be anxious and agreesive during initial introductions. She likes to snuggle, knows which furniture to stay off of.

She is a 10 year-old, healthy, female ACD mix with a history of anxiety and has bitten our toddler twice now. She needs to be rehomed, but we are not having any luck despite trying for the past 6 months. Shelters won't take her because of the bite history and no one seems to want to adopt her.
We made an appointment for euthanasia with our vet, but brought Suci back home to try some new anxiety meds and to make last attempts at rehoming.
Can you help Suci?