I took Oscar (our youngest retriever and the boss) to meet our rescue pup that we have reserved. He wagged his tail at her, then she jumped at his face and he snarled at her - he didn't do anything, just told her off. She then backed off and they walked on the lead together perfectly well, he was pretty much ignoring her but didn't snarl again.
They haven't been off lead together yet, we're doing that on Friday - I shouldn't be worried about the fact that he told her off in the first place should I? I know this sounds stupid but I do love her, Bailey has met her on and off lead and was happily leaping round the play area with her.
Am I worrying unnecessarily?

Sorry about all these questions recently!

He was just teaching her manners. :)

Sounds pretty normal to me, my two older dogs aren't terribly patient with rude young dogs and any that tried to jump all over them or put their paws in their faces would be put in their place pretty sharpish. I bought in my youngest dog last year at 5 months old and my oldest bitch did nothing but growl and snap at her for the first week or so, I wasn't worried about it, let them sort it out themselves and the pup soon learned how to behave. They get on fine now although the youngest one has now very much asserted herself as the boss dog. Oscar sounds like a very good teaching dog for youngsters!

Thank you both, he is very good after the initial 'back off', but my mum was refused a dog from the same shelter previously because her older male dog did the same thing to a younger bitch they desperately wanted to give a home. I think that's what worries me, I have fallen in love with her and don't want them to say no just for this reason.

I wouldn't worry either :)  My 12 year old regularly tells my youngsters off especially when they are larking about around her, but they do respect her and other times, she will happily play with them, on her terms of course! They do need to learn manners. :)