By asking another question.

You think about it for a second. If this is really what happens, then you need proof. You turn to look at your mother and think. She’s around 5’5” so not exactly the tallest and she has complained about not being able to reach things before. Why not?

So you ask, “Hey Mom, would you rather be a little taller or a little shorter?”

She doesn’t even stutter as she answers near instantly, a total contrast to your first question.

“I’d rather be taller”, she says.

Then, just like before, it seems that some magic enforces the choice. Your mother slowly creeps up in height, becoming a good four or so inches taller. But, she doesn’t seem to notice. This only inspires further confusion. Do people not notice if someone doesn’t perform the action? So you ask a different question.

“Mom, have you always been that tall?”

She doesn’t look away from the still cooking bacon, saying, “Yeah? Pretty sure I’ve been above average for a woman my whole life.”

This deal just got a whole bunch sweeter. Your hormone addled mind just can’t wait to take advantage of this situation.