Flower girl outfit

[TodayIsTheBestDay]

My lovely DSIL has asked DD (6yo) to be her flower girl. My nieces - DSIL's daughters, aged late teens to early 20s - will be her bridesmaids.

DSIL is very relaxed about what DD wears, and has said she just wants DD to be comfortable, but I want to make sure I get it right! I want her to fit in well with the bridal party, but obviously in a junior/simpler style.

DSIL will be wearing a floaty, lace, creamy-white dress. Her bridesmaids haven't chosen their dresses yet, but I think they are planning rose/red, probably satin. The bride is aiming for a romantic, vintage feel, and the wedding will be relaxed and happy.

So...
a) Flower girl dresses often seem to be white. Would that be the best, or should I coordinate colour with the bridesmaids dresses? Would just a sash be enough coordination, or should the whole dress be e.g. a paler shade of the bridesmaids dresses?

b)Given that DSIL will be wearing lace, should DD wear a lace dress too (there are some very pretty monsoon ones) in order to match in style? Or should she wear satin, to not be too similar to the bride?

c) Or if white lace is too close, would pink lace (if that coordinates with the bridesmaids) be suitable ?

d) I'm thinking probably flowers in her hair?

e) Anything else I should think of?

I know I'm over thinking this, but my DSIL is truly lovely, and I want to get it right!

Btw, DD will of course also have input, but is fairly persuadable - and she will love any of the options, especially when we add pretty shoes and accessories. She is unbelievably excited about it

Your sister in law should be choosing and paying I would have thought?

SIL is very chilled, and has said she is happy with whatever DD would like to wear.
She is the opposite to a bridezilla

PILs have said they would like to pay for the dress, but I really wouldn't object to paying for it.

We will go shopping with them when we are next there, but I think having some ideas ahead of time will help. I also thought I'd take a few (returnable) options with me in case we don't find the right dress. We live far away and won't see them many more times before the wedding.

Monsoon dresses are always lovely for flower girls, my 7yo DD loves them. For my sister’s wedding I ordered a few and let my DD choose

Monsoon always have lovely dresses for bridesmaids/flower girls

Just have a look around both a lighter shade of the bridesmaid dresses or a white dress with same colour sash sound fine.

Find out what flowers the bride is having so she can have the same in her hair