Text box and button text change size when opened by another user

I'm working collaboratively with another Storyline user. I do a draft, she records audio and gives me feedback, and I polish content and adjust timing.

The problem is, when she opens my .story files, the text boxes and buttons I've carefully sized to fit the text now have text overflowing them. (I'm using the default Articulate font, 12 pt in text boxes, button font size varies).

We've verified that neither of use needs to update Storyline (she had been on an earlier version, but updating does not appear to have fixed the issue).

Any suggestions or assistance would be appreciated, thanks!

Jenny Nilsson