Always have your dog on a leash and hold your dog under your legs and don't let any dog come up to you if it is skittish. I would just protect her until she is more confident. You show her and any other dogs you meet you are the boss.
If you limit the problems when dogs meet then you encourage the dog to become more confident which will help her socialize.
One way to neutralize a situation is let the dogs smell some food and make them beg for it. Don't just dish it out. Get the dogs mind focused on the food and make them sit and then get rewarded. This stops them being focused on each other.
You say the scottie bit your dog on there second meeting. If you were using food then maybe the dog would be looking to you rather than biting your dog.
You can also use your own body language to tell dogs not to approach you. This is really good for males looking for your female.
My own girl didn't like to socialize and I never pushed her and now at 3 she is good with other dogs. She Knows how to deflect attention. She does live with 4 other dogs though.
I know most people aim to socialize when young but I think there is no rush. Easy easy, little by little is the way.