The PlayStation 3 and Vita versions of this mission are related to a trophy named "Hot Babe", completing this mission will reward you with a bronze trophy.
Halfway through the starting cutscene you'll be ambushed by Marauders, both marauder buggies as well as standard marauder units. The buggies mainly drive in circles and fire a couple shots at you which aren't that dangerous, but it's not really possible to avoid them on foot so stay close to the water. The marauders themselves are a bit more troublesome but they are not very strong and as long as you keep the heat from your weapons up they shouldn't pose much of a challenge.
You need to kill 60 enemies (a buggy counts as one too) to win this mission, any weapon is recommended here, including Dark Jak as well as Light Jak for your new Light Regeneration power. Ashelin will be fine on her own as long as you draw all the attention at you, there's too many enemies if she is left alone to stay in front of her.