Help! My ex gf invited herself to my tech school graduation, should I tell her no?

My ex gf and broke up about 3 months ago. We spent the last month of our relationship fighting. She started dating soon after our relationship and currently has a new bf. We've only spoken twice since the break up. A week before my grad she starts chit chatting over text about random stuff. A day later she starts chit chatting over text again and asks the time and date of my grad. Should I tell her she shouldn't come.?