Clarke:
Not that much
She wouldn't mind a hug or holding hands but anything further than that no.
She might kiss you on the cheek if she has to go but that'll be it.
Lexa:
None
She always showed her affection towards you behind closed doors mainly because she was heda and had to set an example. Also she didn't want her enemies to know her weakness again.
Octavia:
ALOT
She loved it. She wasn't afraid to show everyone that you are hers. There would always be so some sort of pda going on. But she really liked to sit you on her knees and wrap her arms around you.
Raven:
Alot
She eventually eased into your relationship and once she felt comfortable she would always hold your hands or kiss you. No one stopped her and you didn't mind at all.