Hi and welcome to the gmb.
This isn't really my area, but I don't think it's likely to be possible to pin down a maker or place for Mary Gregory style glass - it was very much a cottage type industry, "Mary Gregory" was not a person!
Mary Gregory glass has been made in recent years, certainly in the '70s; and I've been told the way to tell whether or not a bit is old or new is to look at the way the figures are executed.
On old pieces, the children are quite chubby - conforming to the ideal of the time, while newer bits have slimer, cuter children - conforming to today's ideals.
I think you have a rather cute, slim modern looking child on this piece. It's nicely done.