puppy to submissive?

When I take ruby for a walk, she always runs up to other dogs sometimes she does this slow strange walk wagging her tail, she rolls over on her back and people always say aww shes lovely and thats how you want them to be. I do worry however if she does that and just gets attacked, or if shes in season and gets 'caught'.
ive never had this with my other staff she use to just run up and jump at people and you would be apoligising to them,

I thought this was just mine lol Smokey rolls over everytime she sees another dog

Haha yeahh she does and because shes white she gets dirty all the time haha, she does this weird slow walk towards them and then rolls over people always laugh at her lol

Better that way My Vin always promptly lies down on his belly when another dog comes towards him, he is just saying its ok I am friendly

Bo used to roll over but he's stopped that now. Now he sits down or sometimes lie down until he's decided the oncoming dog is not a threat, at which point he rushes at it until he's nose to nose, his tail wagging so fast it's a blur.

^^^ exactly what Vinnie does

If you want to reduce the likelihood of her getting attacked - don't let her run up to random dogs? If you don't know the dog and she hasn't met them before, don't let her approach without chatting to the owners first. If she's showing strong appeasement gestures as you have described, it would suggest that she is possibly a little under confident and a negative experience with another dog could really knock her even further, possibly resulting in fear aggression on her part.

Why on earth would you let her approach other dogs if she was in season? If you're walking her when she's in season she should road walked, on a short lead at off peak times and not be coming into contact with entire dogs.

I let her off her lead, she listens alot of the time just sometimes she runs up especially when she knows the dog, and okay thank you :-),
Well say im walking her on a lead which I would if she was in season, but what if someone elses dog comes up to her, say im talking to the dogs owner, its just a scenario

Listening a lot of the time isn't really acceptable though, have you tried using a long line with her? Off lead dogs running up to me and my dog are the bane of my life, it's bad manners and technically an out of control dog. Not everybody appreciates an off lead puppy getting in their dog's face.

Well, if you were road walking her on a short lead the likelihood of an off lead dog approaching would be minimal, as very few people walk their dogs off lead on a pavement. If you were talking to the dogs owner, you would ask them to put their dog on a lead as yours is in season.

Yeah I have but I dont feel like its enough exercise for her, and I know I do try recalling her with treats and shes good alot of the time but like you said its not really good, what else could I do to help try and get her to come?
I dont really walk on the road as theres a woodland 5minutes up the road,

How old is she? Harrie was very submissive up until about 4 months old now she only rolls on her back with dogs she knows while they are playing.

Shes 7and a half months, she is really good with dogs especially other puppys when there playing with her very tolerant I think, when she goes up to them dogs she doesnt know she does this like, well it looks liked she would be weeing but shes not she had her head down walks very slow ans her tail is wagging then rolls on her back haha