Do get your own account.
Not only so you can see what she posts, but so you can have fun with her in this new way. My dd loves to teach me about new features, send me funny things, and be the first to like my posts.
Let her know from the start that you’ll have her password and that you might log in to her account and read dms from time to time. Like others have said, it can be a fun way to connect with people, but there are dangers and friends can be mean. I rarely check on my dd, but my friend has her own account and her dd’s open on her phone and reads everything every day. Determine how you want to handle it when you set it up. It’s very hard to get more control but easy to loosen it up as she proves herself trustworthy. Also think about time limits since it can really suck you in. Talk about not comparing yourself to the perfect little snaps people show, and be prepared to deal with sadness over seeing pics of friends doing things without her, that kind of thing. It will be good to walk through the world of social media with her.