Well that's good, there won't be any overly awkward reintroductions here. Upon hearing the knocking, she calls out, "Ella! Get the door!"

...

Oh wait, she wasn't around, was she? She frowned as she went all the way down the stairs (So inconvenient, gosh!) but when she opened the door she was all smiles- And well dressed as always, "Oh! TARDIS! I'm glad that you could make it. .. Would you mind terribly if I called you Sidra for short?" Beat. "Anyway please, please come in. Really, come in."

She'd take the ship's arm and drag her inside if she had to.