It depends on the relationship you have. I had a very similar experience and because of her demeanor and the context of our relationship, I knew she was flirting with me (and she told me so later). If it had been a different friend, that probably wouldn't be the case. If other people who weren't there are telling you it was flirting but you didn't get that vibe at all, it probably wasn't.
There is more. She was saying some things and mind she was drunk. She was trying to keep me by her side. When I was gonna leave and came back, she was like no one takes away my (my name). She also said I love you. I don’t know, normally she acts flirty with everyone but this was like just towards me.