when lydia said “they saved me mom.” and then added “stiles saved me.” she wasn’t just talking about physically. 

the way she laid her head on his shoulder and wrapped herself around him in the jeep. the look on her face when she said you came back. the way that lydia smiled so many times at stiles in this episode, making her look more content than i have ever seen her in the history of this show. when she opened her eyes the only person she looked for was stiles. lydia thought stiles was going to die, stiles thought lydia had died. when she woke up, the look on their faces of seeing the other alive had more relief and more emotion behind it than i have ever seen in this show. they intertwined their fingers just to prove to themselves that they were both real. that they were both alive. stiles saved lydia physically, emotionally, and existentially and she does the same thing for him.