I'm not sure what the rules might be for when this involves hyphenation or the creation of a compound word and when it stays two separate words, but at a descriptive level they must be fairly fluid, since native speakers writing casually (e.g., in LJ entries) often vary which form they use within a single piece of text: 'lip balm' in one paragraph, 'lipbalm' in another. I'm sure it's the sort of thing copy-editors (there's another) spend a lot of time tracking down and forcing into consistency.
So. Does Hindi do this?
(I'm still looking for passably natural ways of saying 'foster-mother' or 'adoptive mother' and 'birth mother' or 'biological mother.' For 'birth mother' machine translations of course just give me 'birth' and then 'mother' and I have no idea whether the two words mean anything stuck together. For 'foster' as an adjective, http://www.shabdkosh.com/ gives me 'धात्रेय', which Google Translate simply transliterates, implying that it's an unknown word. For 'foster mother,' Google Translate gives me 'धात्री,' 'पालक माता,' or 'धाय.' shabdkosh.com doesn't recognize the first or last of these, and only gives me piecemeal (thus, non-idiomatic, thus gibberish) translations of the two words in the second.)
* Now, there we have a noun modifying another noun, but if I hyphenated it, it would change the meaning: a 'woman mentor' is a clumsy phrase - I should probably have said 'female' to simplify things - but it is clearly understandable as meaning 'a mentor who is a woman.' Whereas, a 'woman-mentor' would be someone who mentors women - a skeevy-sounding proposition at best.