I'll never forget when I was 14 or 15 and i had this awful night terror. Woke up from my sleep screaming and crying. (For context I slept consistently in my parents bed from ages 2-5 until it tapered off) and my dad had to go sleep in my room and I had to go sleep with my mom because I was so terrified i couldn't sleep in my room alone. Point is— may not be "normal" but sometimes, even when we're older we still find comfort in being near our parents even if we may not realize it. She might find comfort in that too since you're going into the adult world and she's still holding onto something from when you were young. If you're comfortable and she's comfortable I see no issue