Milkshake looking oil? The OP could also check for oily coolant as well as low coolant level.
Some of the 2.5s suffer external HG failures that are easily spotted and easily managed while an internal leak might exist for some time undetected.
The OP could check the glovebox for records. You'd be surprised what you find in used cars. There is a very good chance that this engine has already had the HGs done, which would also mean that timing belt service has been done. If done properly, there should be no further issues.
This is a pretty cheap car if it's in overall good condition. If it is, then even a HG job might be worth doing.
An AWD Subie would be a good pick for a young daughter in areas that see severe winter, like SD.