If we’re less than 3 players, she’ll play as an NPC as well. A lot of the times when it’s just us, we’ll either do a super balls to the walls session 0 character creation, or we’ll basically play test some of her campaign ideas as 2 players. Most of the time it ends up being much less structured, so more wiggle room to poke holes in plans, so it ends up being great practice for both of us.
Crobat! I always add it to the party if it’s possible.