Do these two sound equally natural? If so, is the meaning the same?
She is enjoying her college life there.
She is enjoying college life there.
How about She's enjoying her life at college?
1. "How are you enjoying life in the navy?"
2. "How are you enjoying your life in the navy?"
The asker of 1. is assuming that "life in the navy" consists of certain things. He's asking how the person is enjoying those things. The asker of 2. is putting more emphasis on the person rather than the type of life.
In any case, they could be used to mean the same thing. But in reality, I believe that 1. is more colloquial and 2. is not as common. Therefore, they don't sound equally natural - which was the question.
PS: The case could be made that someone who is enjoying her life at college, but is only staying in her room studying constantly and not socialising at all, is not enjoying "college life" as it is generally understood.
Sorry- it was meant more as a possible alternative for Taka.
OK. Then what is the difference between that one of the present progressive and this?
She enjoys college life there.
Present progressive carries an implication that it is either new, or temporary, or both. (At some point, "college life" comes to an end. Graduate for most. Too much enjoyment of that life can cause an earlier end for others.)
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.