Did Trish have work done or is her face just drying out?
*assuming she doesn't smoke or tan on the regular*
It's because she's so thin. The older you get, the less collagen you produce and thus the thinner your skin appears. The thinner your skin the more prominent lines and wrinkles are. Like, even with her weight loss Mickie is still thicker than Trish so her skin looks plumper so her face hasn't "fallen" in the same way.
It's why instead of face lifts some folks just opt for fat injections under the skin to fill out the face.