i agree with classes - they are fantastic.
In my opinion, you need to get visitors to ignore her, turn their backs, cross their arms and not interract with her when she is jumping up and down at them. Then when she sits down or leaves them alone, treat her (either with food treats or a game) you may need to do this several times before she realises that she gets rewarded for NOT jumping up, and if she jumps up she is not getting any attention (remember that to puppies, shouting and hauling them off is attention, which is what they want) It needs to be consistent with all visitors (if you have people round you can't prime beforehand, then put her out of the way when they come) and with you too - whenever you come in, don't make a fuss of her till she stops jumping up etc - just turn your back on her, cross your arms, ignore her, then make a fuss of her when she ignores you/calms down/sits