Any gull behaviour experts here?

The female is often there, settled comfortably on the roof, coming over to stake out likely looking people or to clean up scraps when people have eaten their lunch and departed. The juvenile is very often with her. He begs constantly, and she tolerates him, just backing or walking away from him, never regurgitating for him that I’ve seen (since October) but never aggressive either. She protects him - closely supervising and chasing off any other gulls who fly near, and usually letting him eat. She now usually comes and take food for herself as well, but is still indulgent of him; guiding him (eg to the shoreline to forage), letting him feed first, and tolerating him following her around and begging constantly. 

It’s the interaction with her mate that I’m particularly interested in. They are obviously a pair - the male will often land nearby and the juvenile immediately runs over begging for food from him. The female will tolerate the male (when she aggressively chases off any other gull), but not too close… if he gets too near or attempts to feed, she will attack him quite violently, from running at or dive-bombing him, through to grabbing a wing and holding on (eg if he’s actually taking some food that I’ve offered the juvenile). She will sometimes tolerate him on the flat roof for a brief period, but will then display varying degrees of warning or threatening behaviour until he flies off. This is very obviously different to how she reacts to ‘intruders’, though. 

The feeding territory is very much guarded and reinforced by the female, whilst the male is generally settled on a nearby rooftop. He will also swoop in to defend her territory, though, especially if, eg other gulls see a food source and start circling - the pair will then drive those gulls off, before he resumes his distant perch. He tolerates the juvenile too (also not regurgitating but just walking or backing away) but if it’s just him and the female isn’t present, he will try to steal the juveniles food.

I hoped to see some pair bonding behaviour by now (March) which would give me clues as to whether I’ve correctly identified the sexes. It’s hard to tell which is the larger, as it varies according to their posture. Am I right in identifying them as above, or is it more likely to be the male holding the territory and the female on the sidelines? The one I’ve identified as female is the much more ‘hands-on’ parent, still, and definitely calls the shots… which I guess is why I’ve assumed her sex as female.