Yes, Chair! That particular line change is pobably the most "needed" change in the dialogue from the current revised version. I only have the original, published libretto at hand, so that one escaped my memory.
If we are being super technical about the time frame as far as when the Witch goes to fetch Rapunzel, I was say it is likely a bit less than 9 months, as she would have had been pregnant before being banished and because the Baker's Wife, who becomes pregnant AFTER that banishment, is still visibly pregnant after the Witch, Rapunzel and her Prince return.

the Central Park production had a wonderful effect where the Wife becomes visibly and heavily pregnant as soon as the Witch transformed, but THAT drove me absolutely bonkers because it totally ignores that time frame.
Very true about Grimm's tales always having a healthy dose of nonsense... As far as her noticing, that always struck me in relation to the magic we DO see. We do not really see the Witch use magic for casual purposes... I mean, as I said before, she manually climbs up to Rapunzel and THAT is a strain to her. She generally only uses it to freighten and harm. The one exception that springs to mind is bringing Milky-White back to life... even that is completely self serving and a desperate move as the clock is about to strike 12. Perhaps regaining her beauty left her in SUCH a happy place that she was not out unleashing havoc and terror on others and Rapunzel just broke that in two,