While I really enjoy the Tomb Raider Franchise and I did enjoy this movie (moreso the second time around!), there are some things to be aware of. SPOILERS ahead, so please stop reading now if you don't want it ruined!
-The main antagonist falls into a pool of acid and resurfaces with his skin burned off, screaming and thrashing around as the acid eats through his muscle. This was probably the most disturbing scene in the movie. You have a few seconds warning before you see him dying, however, so I advise you look away once he falls into the pool.
-Lara and her partner/love interest roll around on the floor mostly naked, kissing and caressing each other. However, Lara handcuffs him to the bed and leaves without him (because she isn't sure she can trust him after he almost got her killed) before they can do anything. The love interest responds to getting cuffed by saying, "Not what I had in mind, but..."
-Aforementioned love interest slaps Lara on the face, hard, during an argument. He then reaches for his gun to shoot her, but she shoots him first. All you see is their faces, and then him slumping forward onto her shoulder as he falls. This is probably the least concerning of my three points, but it disturbed me a lot when I was 15 or 16 and the movie had just come out.
It might be a good idea to talk to your kids and make sure they understand why Lara treated Terry the way she did. Originally I thought she was just trying to get ahead of him by tying him up, and that she'd shot him for not agreeing with her or slapping her. However, when I watched it again a few nights ago I understood that she was doing those things because he was threatening her life in varying degrees.
Personally, I found Lara to be a stronger and more interesting character in this movie than the previous one. Despite her reluctance to work with the government (and apparent great distaste for it), Lara sought out Pandora's box in order to keep evil people from getting their hands on it and killing "millions of innocent people". She also refused to hold the box ransom for millions of pounds from the government, instead destroying it. I felt that the overall morals conveyed in this film were better than the previous, in which she endangered the universe just to find out what happened to her father and possibly see him again! Lara may be true neutral, but I just didn't see her behaving that way.
Also, as far as role models go, I think Angelina Jolie is one of the better ones for teenaged girls. She's a successful woman, a good actress, a loving mother, and an inspiring humanitarian. I think she did justice to Lara Croft and can't complain about her personal life very much.