Have you ever taken her to the range? I know you are not in the best situation financially, but if you want her to be okay with firearms, you need to involve her a lot more with your hobby shooting before she will feel okay with the idea of using a firearm as a defensive tool. Take her to an indoor range that allows to you rent pistols and the like, and have her shoot what she wants. See what she thinks. If she enjoyed herself, you and her could pick out a good home defense firearm together. If she thinks firearms are dangerous, maybe you should tell her that you'd get a safe. You need to think from her perspective and try to correct any issues she might have.
I understand if she has no interest in going to the range with you, I really don't know what else I can suggest.
Good luck, I hope you'll be OCing soon.