Hi Chris, some great shots recently. I feel a bit unsure about offering crit as your lighting skills are well ahead of mine, but here goes...
Week 21 - a very striking image. The overall lighting works well and is very dramatic. The grainy processing works well on her hair and jewellry, but seems too harsh on her skin - almost makes her skin seem broken. I'm not sure about her position in the frame - seems too tight in on the right. I think it would have been better if she was in the LHS of the frame.
Week 22 - great shot. Lighting looks perfect to me. You've caught a lovely expression and pose, and the eye contact is beautiful. Like the reflection too. Very professional.
Weeks 23/24 - two excellent shots. Really liking these. Great use of OCF. They both have a very romantic feel. You've balanced the flash and ambient really well to bring out the wonderful backgrounds. I'd be tempted to clone out the hotspots on the cheeks/chins in week 23.