I admit -- I do not usually label my quilts. Have you looked over it carefully to see if there is a signature/date somewhere? Could be front or back. Family photo albums are a great help, so if you see a quilt in the background or with a gift shot it can help too.
Even if we can narrow it down a bit, it's pretty rare when we can precisely date a fabric unless someone has a definite memory of a particular piece -- so I'm only good down to the 1970s. Patterns are similar/reused but sometimes at different scales. Children's prints particularly can be hard to date, but there are still clues. There are some things like some dyes that are definitely dated because they didn't exist before certain times, or designs that were popular in particular periods.
The rule for quilts (or anything vintage really) is it is only as old as its newest piece. Quite often we do see scrap bag quilts that may be predominantly from the 30s or 40s but maybe not constructed until later, so we will have mixed prints and a solid background for example.