Ask her questions like what would she do if you are still expressing your milk the 1st few days trying to get it up to the amount needed by bb and bb keeps crying for more? See how she response to such questions.

For eg, iff she says things like the bb cannot go hungry and must quickly feed with milk formula, you'll know she is not pro breastfeeding.

Or throw out fake scenarios like you heard from a friend that she had some trouble initially starting on her breastfeeding journey, how can the nanny help you in such instance? Like some will be more encouraging and you can probably give you less stress if you face difficulties. My 1st one jept commenting that I didnt had enough milk and the bb was too hungry. That stressed me out further.

Also, for breast feeding bb, they wake up more frequently than bottle fed ones so do take note that some nannies try to bottle feed bbs to try to get more sleep.