What I find amusing is that although Helen may like expensive shampoo and her daughter may have some French clothes, she dresses quite casually and is generally unadorned, yet the future Alison is dressed from head to toe in expensive gear, with a sharp haircut. I'll wager that she has designer shampoo now.
As to Noah not telling Helen that Scotty was the father, I think that was as others have said, because he was a Lockhart (it's more or less the first thing he tells Max) and was, no doubt, aware that the link to the Lockharts could open many more cans of drug-dealing worms in which Alison was directly implicated. Of course, the reality was that in that moment, he was totally pre-occupied with his own needs and not his daughter's or his wife's.