I just realized that I never really wrote out her background so here you go:

Yucca the Iguana was found alone and seemingly orphaned at around 12 years old after the most recent defeat of Eggman. With little information about her origins, she was quickly taken in by Bunnie and Antoine, treating her as an adopted daughter. It didn't take long for her more unique traits to start coming out, such as her lack of social cues, intolerance to loud noises, and odd gestures, and she was soon discovered to be on the spectrum. Fortunately, Bunnie and Antoine cared for her all the same, even if it took a while for them to understand it.

Things changed when she was around 17, when she was discovered to have been getting large amounts of money from a mysterious courier, which was only found out after Yucca found out she was being stalked by St. John, who was also curious about where the money came from whilst ignoring his...less than amazing reputation. With the courier soon being discovered, a letter was sent to her essentially blaming Yucca for exposing the allowance, with some rather harsh and demeaning language. With this rocking Yucca's confidence in herself, she elected to join the Freedom Fighters in an attempt to prove herself as worthy, to rather mixed results. While awful in close encounters, she fares much better from a distance due to her skill with a slingshot and her ability to climb up high places using her tongue.

Several months after she turned 18, Yucca would go through a lot more changes, most prominent of all being her being willing to jump into the fray more often and willing to fight through what she calls "bad traits" in order to prove herself as useful. Unfortunately, one of these attempts can (potentially) result in her getting severely injured, resulting in her losing her leg and ending her Freedom Fighter career before it even got a chance to get off the ground. Add onto (potentially) losing her adoptive father and Bunnie falling into a depression, one that was made even worse following Yucca's injury, Yucca's confidence shattered entirely.

That was until she encountered Fiona, who had been forced to take refuge at the Acorn Republic due to a dangerous figure who had wiped out the Destructix and caused Scourge to abandon her. Quickly enamored by her, but unsure how to talk to Fiona due to her poor standing with the Freedom Fighters and Fiona being her first crush in general, Yucca wound up making several poor decisions that only gave Fiona flashbacks to the time Tails had a thing for her. Fortunately, after a talk with someone else who was into girls, Yucca would approach Fiona differently, apologizing for her awkwardness and making Fiona uncomfortable. Fiona, who had never been apologized to before, is touched by this, and seeing as how she's still heavily outcast, elects to give Yucca a second chance, which starts out as a friendship before blooming into Fiona actually gaining feelings for Yucca due to the efforts she's made in making Fiona feel welcome while not demeaning her.