My baby is terrified of other babies.....help!

[Nancyclancy]

My dd is 18 months old and has much older siblings. We regularly see a friend of mine who has a dd who is 6 months younger. For some reason my dd is terrified of this little girl for no apparent reason.
She is on edge in her company, cries when she sees her and screams hysterically if she comes near. Yet other babies she doesn't mind?

It has upset my friend because she has had a similar problem with other babies reactions to her dd too, although not as bad.

I'm not sure if my dd's behaviour towards her dd is becoming a habit. I can't work out what to do. Any advice would be appreciated!

Is it just this baby? Has she met other babies/young toddlers? Are these meetings at your house , theirs or out somewhere as setting may make her less comfortable.

She's fine with other babies. She doesn't seem to take much notice of them. Babies the same age as her she's ok. Older toddlers/children she loves.

This particular baby has come to our house, we've been to her's and to toddler groups. My dd's reaction is always the same. She's ok if she's not too close but if she's heading her way my dd starts crying. It's so strange. This baby is quite advanced physically and will try to hand my dd toys, even offers my dd her dummy. She's a sweet baby.

It's getting to the point where it's hard work meeting up. My dd is driving me mad. If this other girl was horrible to her then I could understand but she really isn't.