Creighton - the gist of what Jack, Kate, and Karen are saying is that you have a bigger problem than equity structure. You can come up with any sort of equity structure you feel comfortable with, but what you have in reality is a co-founder that lacks the tools to be a cofounder (the reasons only matter peripherally)
You have a couple of choices:
#1 has the downside that resources are scarce in a startup and the more you spend on bringing someone up the skills gap, the less you have available to make the company successful. Yes EVERY startup has a skills gap... but the question is how overcomeable is this one including the issues of willingness, skills, time, and costs
#2 is a variant of #1 except that you don't proactively spend the resources and instead the energy goes into cleaning up the bits that get dropped
#3 requires that she be upfront about what she can and cannot contribute and in essence you set aside some equity to bring in a 3rd cofounder to fill in the gaps. This is very hard to do as so many of the "looking for a cofounder" threads attest to
#4 means she essentially sold you her idea for equity. Probably the best approach but the hardest to get her to go along with
#5 is probably the easiest. There are lots of ideas.
Its not an easy choice (and there may be other paths you can take as well) - but you need to decide how the business is going to function to achieve success BEFORE you start dividing up shares of as yet non existent value