Have name changed to something fitting for this, I post once in a while 
Just as a background...
I was brought up speaking Welsh and English at home with my grandparents having absolutely atrocious English and not learning it until their 20s.
I married a boarding school boy with a background very different from my own. He doesn't speak Welsh although clearly the family name has Welsh roots.
In my workplace we speak 100% Welsh and so naturally I still speak that more. I speak both to my children and English when husband is around. We live in an English speaking area although our small village being about 50:50 and so church is bilingual.
The children go to a welsh language school too.
DMIL.....
She resents that they speak Welsh and often comes out with comments like "oh only backward, uneducated poor people spoke Welsh when I was a child"
"It really does hold you back" - no it doesnt we have two medics at uni thanks...
Etc... it's not 1940 ffs
She always tries to prove that it's a waste of time, claims they don't speak it outside of school, frowns when she realises they speak it with their welsh speaking friends.
They pay for us all to go on a big family holiday and if they hear us speaking welsh we were once told to speak english when they are around. Ok fair enough if they are part of the conversation etc.
She makes comments when I'm around like " I find it very rude that you speak welsh around us"
BUT !!! Their cousins are bilingual Spanish and speak Spanish with their father (spanish) at the dinner table and she would NEVER dare say anything about that. I just feel like our language isn't viewed as real.
AIBU to tell them to stick up for themselves and be proud of having two first languages?!
God I want to smack that woman out sometimes...... as lovely as she is other times..... 