score:3
It should be no problem. I have done this many times for others and family members frequently do this for one another for various reasons.
There are apparently some odd regions where the bearer of the ticket is asked to show the credit card used to purchase the ticket but I have never experienced this in decades of travel across 56 countries and so I am only mentioning this because another question on this site asked about such a case.
In any case this happens in tons of situations such as buying tickets for a group, buying tickets from a corporate office for employees, etc. It is hard to think of any reason why a genuine ticket would not be considered valid.