Jill had to admit that it was at least an interesting experience. Aside from having been put in a dress mom was somewhat right. Who cared what he peed out of when it was basically always into a pull-up or a training toilet? Plus with tablets and videogames nowadays they were able to have a lot of fun without a lot of responsibilities. Jill did try to not make too much trouble for their mom. Then the weekend was about up so Jill and Mark were in the living room with their mother who had the chronivac emitter.
"Alright Sweeties, whose ready to grow up." their mother asked and her kids raised their hands. Their mom smiled and then hit a few buttons and the kids could feel themselves growing.
3...4...5...6...
"Um, mom... my pee pee isn't coming back." Jill said
7...
"Yeah, we're turning back to normal right?" Mark asked
8...9...10...
"Mom?!?" The two of her kids asked
11...
"Hey I just asked whose ready to grow up." their mom said defensively
12...
Jill said "Not funny. My chest feels weird" as her nipples were starting to enlarge.
13...
Jill noticed that she was starting to grow boobs along with her hips getting a little wider as her curves were being prepared. Mark on the other hand felt his penis get a little sensitive and larger as he ended his progression. Jill on the other hand was still on the growth train.
14....
Bit by bit her breasts swelled year by year.
15...
B-cups last year, C-cups this year and a nice soft ass to match...
16...
Jill sighed as her growth ended with her long hair, mighty curves, and full D-cups that threatened to continue growing in the future. Jill groaned a bit as she lifted her breasts up a bit with her arms, trying to give them a bit more support as she said "Mom, can I go back to being Jeff? This feels weird to me."
"Yeah mom, can I get my second X chromosome back?" Mark complained
Their mother put a few commands in the chronivac, but to give herself back her proper age without actually aging herself as she said "No... Just a small experiment shall we say. I've heard about transgenderism more and more, and I'm now curious about whether or not you both would feel more comfortable as the opposite gender. I wouldn't put you both through surgery for that... but if we can flip your genders at the literal push of a button..."
"MOM!" her children shouted
"I'll increase your allowances." She said "...Also I put on parental controls so neither of you have much say in the matter. Plus you remember how the Gilding works with your father." The children groaned as they remembered how they acted completely like toddlers when their dad or anyone else unaware were around.
"Fine!" Jill said "But can you shrink my breasts a little. These things are heavy."
"No can do. I want to see what you both feel like in your actual transgender bodies. Not modified ones to be more convenient or attractive or something."
Jill groaned and said "Fine, I'll go to my room then." and stormed off in a huff.
Mark asked "You modified them didn't you?"
"Well I wanted to make sure she'd be popular at school and maybe get a little love life."
"Could I get some muscles and a few inches then?"
"We'll see little Mark, we'll see." his mom said thinking about everything she could do with this chronivac.