DD1 says her teacher tells her to mispronounce words

[ilythia]

not intentionally I hasten to add, but she says all her 'th' words as 'v'. Everyone.
This is only recently (since she started reading) and I have corrected her a couple of times but she says that the TA who helps her read says it is said 'v', she is very adamant about this and has shown me how her mouth is supposed to go to pronounce it and everything.
She now gets upset if we correct her as 'you are wrong, Miss X is right, she is the teacher' so I have had to stop correcting it for a bit.

WTF am I supposed to do?

I'd definitely do as senua suggested, mention it in a ha ha kind of way. ("I keep telling dd to stick her tongue out, whether it's a "th" as in "the" or a "th" as in "think" but she will insist on saying "v" or "f"" sort of thing)

As you say, the TA isn't actually trying to get your child to mispronounce, she just can't do it herself. (which is obviously not good, but that's another thread! (My dear cousin is head of a preschool and has always done the v/f thing for /th/))

Good luck!

(bet your TA says "could of" as well....)

at 'could of'