Shocked, but not for long.

"Davy, let me go change and get ready. Oh, today's gonna be so fun!", she says with a giggle. She practically skips back inside the house, you follow, sitting yourself down in the living room. You hear her make a loud gasp when she looks at herself in the mirror upstairs. Soon after you hear footsteps approaching quickly as she comes around the corner of the staircase. "OH MY GOD! DAVY, LOOK!" she screams as she comes into view.

"What is it mom?", you say, unsurprised.

"I mean, just look at me! I've got to be 40 years old again...or younger! How the hell did this happen?" You hadn't heard your mom curse, even so much as an H-word, in a long time. She had apparently been very foul mouthed before you were born and slowly broke the habit as you grew up.

She was quite shocked, but you just wanted her to focus on enjoying today, so you quietly made another change.

"Mom will be aware, but un-phased by her change in age."

You notice her breathing slows as she calms down. Her dilated eyes relax, and she simply smiles. She speaks, "Um, actually, this is really nice. Not sure how it happened, but if it means you and I can have a fun like the good old days, I'm down!" You smile at the calm, happy face of the woman who took you and your sister on rollercoasters, ready to relive those days.

Its almost unnerving to think how much you can effect the mind of another with your powers. Something this small shouldn't be a problem though; your just helping your mother relax and enjoy today. What else would you need to change if she's already so happy?