With respect to Hudson's age, she's at the low end of the range, but I don't think she comes as too young. Ten years ago, she played the mother of a nine-year old in the 2nd half of Dreamgirls, and no one complained. As for the older actresses suggested, most would be too old to be believable as the mother of Inez.
Not a fan of Fierstein for this; I've seen his Edna, and I'd now prefer to see someone else's. I'd love to see Ariana Grande as Penny. For Velma, does anyone know if Elizabeth Banks can sing?
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson