Have you done any obedience classes with her? This is a tricky age for any pup, and you seem to be doing the right thing in general, whenever she gets nervous, redirect her focus to you, not the other dog, just say her name calmly, maybe offer hit a bit of treat if she stays seated and still, or a bit of praise - whichever she likes better. If you can, tell the other person "we're working on training right now, she's a little skittish, so can you keep your dog still for a minute?" Being happy and yet calm with her when she's being a good girl, even around other dogs should help. Remember, as a Doberman, she's very smart - use that to your advantage! And the more tired she is before you see the other dogs, the better - take her for a long walk or run BEFORE the dog park, for example, if that's where she's meeting other dogs!