You mention that you're both PhD-ish-level students, and that she's a research assistants. Is she also a PhD candidate? Or is this an undergrad intern type pers

You mention that you're both PhD-ish-level students, and that she's a research assistants. Is she also a PhD candidate? Or is this an undergrad intern type person? I would suggest that unless she is bringing unique talents to the team, she would not get cofounder status and anywhere near that amount of equity — especially if others have been laboring away without so much equity. If you do give any equity, make sure it's on a vesting schedule, and with the usual 1 year cliff. Then make sure that you have the power to dismiss her without needing your cofounder's vote. Obviously he has a conflict of interest and would be hard pressed to fire his wife (and have them lose equity as a couple). You can frame this as a general rule that anyone with a conflict of interest does not vote on such matters. This honestly would also protect her in the event that she contributes a lot to the business but has a falling out with your cofounder. She wouldn't want him to be able to fire her out of spite.