Hi Katherine,
While I never recommend looking to Cesar Millan for advice for training (there's a very good reason there's a "Do not try this at home!" disclaimer on all his shows), I agree with Andrew's post. Always do introductions on neutral territory, and take the dogs on a walk together. Don't let them meet if one or both are showing signs of excitement, fear, or aggression. Walk them parallel so they can't interact, and gradually get closer together when they are relaxed until they are walking side by side calmly. When they're both calm you can let t hem interact, but separate them again if either becomes agitated and resume the parallel walking. Keep trying introductions when the dogs are calm as needed until the dogs are comfortable with each other. At this point, you can try to bring the dogs back home to see how they interact there.
Don't correct or punish your dog for growling or snapping at another dog. Dogs use growls and snaps as warnings to let others know they have crossed a boundary or that they are uncomfortable. It's the dog version of using your words. These warnings are appropriate parts of dog language, and you don't want to teach your dog that you don't want her to give warnings or the first sign of trouble you see next time may be a bite. Instead, help her avoid situations where she feels the need to warn other dogs by giving her a safe space to retreat to where the other dogs can't go and avoiding giving her resources she feels she has to guard, like food, treats, or toys when other dogs are around. Teach her how you want her to react to other dogs in her home by rewarding the good behaviors (no matter how minor they may seem) and removing her from the situation when she says she's uncomfortable.
Most dogs can learn to interact politely with a lot of time and guidance, but before deciding to host dogs in your home regularly, you'll want to consider what that means for your dog. I'm all for teaching her polite manners because there may be times when she needs to accept other dogs in her space, but she may never be happy about it, and it's her home, too. She should get some say in what goes on there, so if having other dogs around continues to make her uncomfortable, don't do it. A lot of dogs, especially as they get older, get less social and prefer to have their own space, and that's perfectly fine.