In terms of reality TV housemates they've had, present and past, she's been relatively quiet. She's not been overtly sexual like Tiffany, wet the bed like Charlotte, not shagged every night like Stephanie (mind you she was TV not reality TV).
I've liked Marnie overall, barring her and Lewis together. She's been okay.
ETA: Sorry, Steph didn't shag every night, just one night
Chloe and Bear did the shagging this series.