I understand it, I think. The shape your lips/mouth make for the 'li' in 'library' is different than for the 'li' in 'libre' (at least when I try to pronounce the latter as french 'libre' but with an English 'r' which I have the impression is how it's supposed to be done and is also what the parent indicates, might be wrong?). As a result there's this weird movement to go from 'lee' to 'br' and I have a hard time getting a typical English 'r' out of it which I have zero problems with in 'library'. Non-native English speaker as well.