Hi Sewlilly! I am another who lives close to SB but not close enough to have looked into a guild there. I am north about 45 minutes. My suggestion would be to call the quilt store that Sandy recommended -- they are super nice there and will give you good advice. I would assume there would be a good guild in South Bend or in the neighboring communities of Elkart and Goshen. SB is about 45 minutes away from Shipshewana (Amish country) which has many a good quilt store. Shipshewana has a huge quilt show coming up the third weekend of June.
I just googled and there is a quilt guild named the River Bend Quilt Guild - I clicked a link on their website to their facebook page and they look very involved with the community. Their meetings are the second Thursday of the month and they welcome visitors.
I hope your son and family are enjoying the move. I would recommend they take advantage of all the fun which Notre Dame has to offer. Not just the sports, but the free concerts, plays and speakers. Also, on football weekends the fun starts the day before with tons of activities from speakers to going on the field to glee club concerts and, in my humble opinion, the best experience - watching the full half time show of the Marching Band! ( all activities can be found by googling Game Day Activities Notre Dame) Any questions about Notre Dame just PM me! Also, lots of pretty beach towns less than an hour away! and some great museums in Chicago just a train ride away.