Meredith Ramsey is the main villainess from "Terminal Velocity," episode 10.13 of CSI: Miami.
She was played by Jacqueline McKenzie.
Meredith Ramsey is a former high school chemistry teacher who married skydiver Scott Ramsey, who is younger than she is. After Scott was killed while skydiving, his past as a sperm donor was revealed to Meredith by Ryan Wolfe, with Scott's donations resulting in the birth of 103 children. Meredith stated that she was unaware of Scott's donors and his immense amount of children, and claimed that she had no plans on having children of her own when she married Scott.
However, Meredith's claims to Wolfe were proven false after Calleigh spoke with one of the donor kids, Jessica Wyatt, who stated that in an attempt to call Scott, she ended up speaking to Meredith instead--who warned her to stay away from Scott. It was also revealed that Meredith had wanted children, and she married Scott because him being younger meant he could keep up with their kids. As Meredith also revealed, Scott told her that he was sterile, but after finding out about his donations, his 103 kids, and the fact that he had a vasectomy after their marriage, Meredith confronted Scott, who revealed his plans to not have children.
Furious over being deceived, Meredith went on a rampage and broke in the clinic that contained Scott's sperm samples and destroyed them. She also planned to kill her husband, and she did so by slipping a bag of nitric acid into Scott's parachute, which eventually burned through the plastic and burned the ropes, sending Scott falling to his death after his chute opened.
Meredith's villainous reveal was completed when Natalia revealed the stains from the acid on Meredith's hands while she was signing a document, and it was at that moment that she confessed to everything. Regarding her motive, the evil Meredith vented over Scott's obsession with skydiving, and she stated that she wanted to make sure that it would kill him. Meredith was later arrested (off-screen) for killing her husband.