I ripped out the seam and removed the elastic...added about 6 inches to the top, then refolded and re-threaded the elastic...
The top is too large across the back, so I put in a tuck/pleat/fold and when she is a little larger i can let it out and she will still fit

It's 1/2" elastic.

The top front was fine, but the back ended up being about 3" bigger than i needed after I got it on her.
Sigh.  I just doubled it over and figure when she gets a little larger I can let it out and get more wear, but it looks pretty tacky, so what to do???

How would I figure out how wide to make the add on?  Elastic width + inches needed above current level + seam allowance?

Thank you so much for the reply.  I am totally stumped!

Please help me with the shorts, I don't know what I did wrong, but the inseam for the shorts, after i added the elastic top, sits lower than my daughters' panties.  She said but mom, I don't like a short wedgie!

I am a very novice sewer, so i took a lot of time and re-read everything, but somehow i need HELP!
Thanks is advance for any help in lengthening that part.
Rose

Super cute! 

Turtle luv from a fellow sister!

I love this.  You did an amazing job!  I want one just like it!

This is so cute!
I'm going to make this on the back of my neices sweatshirt jacket!  Thanks for the inspiration!

You did a great job on this!  I can't get mine to lay that flat, ever.  But aren't these fun!
And such a cutie with those eyes!

it looks super cute on you!  i really like the ruffle, not too big, just flirty enough!

i can't pic a favorite, but this big mom wants that hoodie tute for the first thing i try to sew for me.     i looooove it!  you are super great at this and look beautiful too.   mad applause for you!