Kind-Hearted
She truly hasn't met somebody she doesn't like, which can often be to her detriment. Somebody like Em could very easily be used and abused in this world, without people to look out for her. On the flipside, she's usually blind to it happening, which in part is why she never has a bad word to say about anyone. She can admire a criminal mastermind just as easily as she can a champion athlete or a mild-mannered bookish type. If you're kind to her though, if you treat her well then she will do literally anything for you.
Open
Em is very much an open book with an uncomplicated agenda. If she likes somebody its written all over her face. If she feels something she will usually share it. This means she can fail to consider consequences before she does things, but it also means that there's little in life she won't try to experience. If she thinks it, she does it or says it, at least 90% of the time. The other 10% is usually reserved for crushes she has yet to act on, but before long absolutely will.
Loyal
Once Em has decided that you're her person (or one of her people) there is absolutely nothing she won't do for you. It's not just that she's quick to make friends, she's the kind of friend (or lover) that will never walk away, not without being pushed out the door.
Thoughtful
What she lacks in book smarts, she seems to make up for when it comes to the things she can and will do for other people. You can mention something in passing and she'll remember it, then find a way to surprise you with it just to make you smile. She's the kind of person who will always know your coffee order, your favourite food, the music that makes you smile or the movies you love to watch so that when you've had a bad day or she thinks you might be sad, she can do things to make it better.
Dim
She's just not the sharpest tool in the shed, though you wouldn't go so far as to call her stupid. She's just not particularly booksmart because most things she reads in books don't excite her. She could probably do quite well with studying if she had somebody to encourage her but nobody expects Em to be smart so she never tries to learn things beyond her interests.
Easily Led
Part of it is her Omega nature, the rest is just how Em is. It's almost as if it never occurs to her to say no in any situation. Whether sexual exploration or misadventure, Em is the ultimate yes-girl. Always happy to go along with whoever she's with, because she gets satisfaction in the happiness and pleasure of others. Being a people pleaser isn't always a bad thing for her, but it would have the potential to bite her in the ass.