Quoting Ryloonjimama:" I believe they are called "parents with prams" in most places. So do you take that in a literal sense, ... [snip!] ... kids should still be entitled to park in them, for easier access walking their toddlers & preschoolers in the shopping centre?"
We have spots in a few of our grocery stores that are reserved for pregnant mothers or parents with small children. Honestly, as a mother of two 4yr olds and a 2yr old, on a rainy or snowy day and if I am taking them in the store by myself, I will park in one of those spots. Otherwise, I say kindergarten and up is not necessary. If the weather is good, I don't park in them at all. My kids can all walk and we are never in that big of a hurry.