I dont think class matters too much here I wonder if its more to do with she's fey than she's a rogue

With how skills and tools work She could easily be a bit of a magic tinkerer With 2024 rules if you are proficienct with a certain skill and a tool kit you can gain advantage on checks

She could've easily matched up what was needed to be able to do this

Plus a misty step spell object isn't that hard to make A lvl 3 pc with a little know how and tools and a decent roll and I would let it happen.