The flood in Munster was on the northern end of the town, primarily north of Broadmoor between Columbia and Calumet Ave. (levee failure didn't help). So north end of town, north of Broadmoor, yeah, I'd stay on a second floor. There are some apartment complexes in that area (unless they've gone condo) on Jefferson Ave just north of Broadmoor (one block west of Calumet Ave).
In addition to WWDude's suggestion, look at the far northwest end of town, west of Calumet, north of Ridge. Lots of older brick duplexes (two stories and a basement), you might find a rental in there.
I have a property in Independence Park neighborhood and am looking for a roommate for my tenant, but need a single. Many homes in that area are rentals tho. You might check Highland. Port D' Leau is a large apartment complex on the south end of Highland that borders Munster. Right on 45th St.
Here's a link:
Port De L'eau - EveryAptMapped - Highland Apartments
Also, just around the corner from there on Prairie is a day care center that a paralegal friend of mine really liked, her child was a bit younger than your youngest when she started using it. Highland KinderCare
KinderCare Learning Centers | Child Care & Education, Day Care Services
Some of the church's have good day care as well. Westminster Presbyterian
Westminster Presbyterian Church WPC- Where People Care
And I've heard good comments about St. Paul's Lutheran Church school:
St. Paul’s Lutheran Church and School