"Neha and her friends are going."
Translation:नेहा और उसके दोस्त जा रहे हैं ।
That sounds unnatural. You can use 'अपने' when there's no conjunction (और), for ex नेहा अपने दोस्तों के साथ जा रही है - Neha is going with her friends.
Oh ok, I get it, you use अपना when the possessive is the same as the grammatical subject. Here the subject is Neha and her friends, not Neha. But in your example Neha is the subject, it makes sense.