My Thai wife and I reside in France.

Next year we are hoping that her parents can join us for two weeks holiday here
before doing the same with her sister in Germany. We will apply in the normal way
for a Schengen Visa for them.

However, they look after, as their own, their other daughter's child, who is 10, and
naturally they will want her to visit with them.

What additional documents are needed for the 10-year old to accompany them?

thanks

The same process as normal: you invite them over, guarantee for them, etc.

Now for your niece, they'd have to have proper paperwork, proving that they are responsible for the upbringing of their grand daughter or permission of the mother and father to take her with them with proof that they're the ones taking care of her on a daily basis.

Thanks - I appreciate that - but what constitutes 'proper paperwork'? Their daughters child is brought up daily with them whilst the child's mother - and father - work in Bangkok.

It would be no problem to get the parents to sign something....BUT...what is the 'something'?

Also, would there need to be three separate Schengen applications?

See the pinned topic Schengen visa FAQ.

Well, I looked there before my posting - it does not tell me.

I know all about the Schengen Visa process - I obgtained two for my wife (before we were mnarried).

It is the legal documents required specifically for my wife's 10 year old niece that I need to clarify.

TLS themselves are unhelpful.

Also...three separate applications?

Thanks - I appreciate that - but what constitutes 'proper paperwork'? Their daughters child is brought up daily with them whilst the child's mother - and father - work in Bangkok.

It would be no problem to get the parents to sign something....BUT...what is the 'something'?

Also, would there need to be three separate Schengen applications?

Consent form is required to take her out of the country.

I'm in more of less the same situation, but we have gone legal and have guardian papers from court. I would not know how to satisfy visa requirements without any official paperwork stating the grandparents are responsible for your niece's upbringing.

And yes, 3 schengen applications.