Help with making a pattern to fit larger child.Please?

Hello,
I'm having a problem with making adjustments in patterns for my daughters. I want to make a couple of dresses using
NEW LOOK 6676 and NEW LOOK 6468 ( basically a sundress) The problem being that my youngest  has a chest measuring  34 but is not in need of a  bra yet.  My oldest is still not developed but I found a swimsuit to fit her that is a store bought size 8-10 or chest of 36 inches( also basically flat chested.) Both have hips that are slight larger than but and smaller than chest.
I need help figuring out how to adjust for not needing the dresses to fit a 'bust" I plan to make some of those cute vests that will help hide the tummy til they slim out. I also need to figure out how to do the same when using patterns to fit sleeves.
Thankyou for your advice ahead:)
MeadowLark

So are these adult patterns? If so, you'll need to rework the bodice area to accommodate the lack of a bust. I would use the pattern size that fits their waist size and then straighten out the chest area to remove the fitted bust area. Make a muslin mock-up or try the tissue paper pattern on them before you cut.

You know, I would recommend not using a woman's pattern for your girls. You might get really frustrated trying to undo fitting areas meant for a womans body and then redoing the pattern to fit your child. I would try to find a child's sundress and enlarge the bodice from there. Use your tape measure to figure out the final bust measurement on the pattern pieces and add to the front and back sides. I know it's not quite that easy and you will need to make some further adjustments (probably elongating the waist and adjusting the armscye) but if you make a mock-up out of musin, you can get a good feel for where you want to go.

Simplicity has some really cute options in kids sizes, including a line of plus sizes for children. Check it out! If you find something you like in those options, you should really go for it! http://www.simplicity.com/index.cfm?cat=1&type=4&sec=81&startrow=1

It's a lot of work, I know, but altering the pattern is the key to getting wearable clothing.  I've been sewing for many years and I've yet to find any pattern that does not require altering, sometimes a lot.   After a while you just know by sight what needs tinkering......but in the meantime....

Why don't you cut the pattern in cheap muslin (if there is such a thing these days) or an old sheet.  Baste rather than sew it. Then ask your child to try it on and pin to fit her.  Draw pencil lines or mark where the pins are.  Rip out the basting and lay the tissue pattern on the muslin.  You'll get a good idea how to alter your pattern to fit by following the outline of those markings.

I do not know how to do the alterations but I do know sizes of kids clothing. Have you looked at the girls plus size ones? Not all the pattern companies make them yet.Butterick, Burda and simplicty do.I do not know if New Look does.The girls plus also has some bust space for girl just starting to develop but has bigger waists and more girlish styles.If you look at regular girls sizes a 34 inch bust is a size 16 but in girls plus it is 14 1/2.The same girls 16 has a waist of 27 1/2 inches and the 14 1/2 is 31 inches so you might need to tighten the waists if they do not have as much tummy.I am currently making Butterick 3352 for a friends 10 year old in the size 16 1/2.Before she got as large as she is now I didtake some patterns to a photocopier and enlarge them.Some of those worked better than others.The loss fitting patterns worked better as the fittings were not as talored. Good luck and happy sewing!