Upvote:6
If you were refused a visitor visa previously, then the fact that your sister has since had a baby will not change the reasons for the refusal. You will need to address the reasons for why you were refused a visa.
Upvote:6
You won't be able to get to the USA to visit your sister; but you may be able to visit Canada or Mexico and meet there. This is easier for several reasons:
A friend of mine (UK citizen) meets their spouse (US citizen) typically in Ireland, because if they were to meet in the UK or the US it would be harder to convince the officer they're not intending to permanently stay with their spouse.