Daughter can plan things well without having to give up her LPR.
* she can apply for reentry permit before leaving (allows you to stay outside for not more than 2 years)
* she'll have to return to remove conditions on her green card before it expires (especially biometrics & interview)
* assuming she staying outside for more than 2 more years she can apply for SB-1 visa to return then
* also she should be establishing strong ties to the US even if she's studying outside like maintaining bank accounts, filing taxes, credit cards, investments, insurance, etc
Also, there are some nuisances that she'll have to take into consideration. Like will studying in India be based on free tuition or scholarship as a resident of US or India. If it will be based on status as a resident of India then there could a perception she's abandoning US residency. Another nuisance - she's taking advantage based on her citizenship and not her residency and that probably might/might be an issue.
In any case, the only ways she can lose her LPR is:
* If she submits form I-407 (if she formally wants to give up LPR) or
* If she does not properly file I-751 to remove CR or
* by an immigration judge