|Conflict Started||Before Season 1|
Paige and Heather's rivalry began before season 1. The girls detested each other until the day of their graduation. Paige often insulted her to her friends.
In Mercy Street, Paige calls Heather's eyebrows "tragically over plucked", and Emma says that her tweezers should be confiscated.
- They were both queen bees.
- They were both on the Spirit Squad.
- It is assumed that Heather is the same age as Paige. As such, she was most likely a member of the Class of 2006.
- According to Marco, the way that Heather "looks" at Paige indicates she had a crush, meaning that she could have been a lesbian or bisexual.
- Paige mentions that Heather had a nose job in Season 1. Manny mentions that she had a bad nose getting in Season 7. Holly J. later mentions that Heather did have a nose job due to the "Sinclair Schanuze" in Season 11.
- Heather's younger sister, Holly J. Sinclair, shares similarities with Paige.
- It is possible that Heather had a conflict with Manny Santos, as Paige did.
- They were both members of the Yoga Club.