My employer will not sign a notary doc. for my appartment application? what do i do?

I'm moving out for my first time with my fiance and baby boy to our own apartments. I work in a tattoo shop and I am paid 50% of the total for the tattoo I do and the other 50% to the shop. I turned in my receipts from all my customers within the last 3 months and the apartment manager still needs a "proof of employment" document signed by me, with the shops information and stamped by the notary also stating the receipts are signed from my clients that I tattooed. So I went down to the shop and explained to them the whole situation that I would need them to sign the document stating what I just said. She told me she wouldn't want to because she doesn't want to get involved with legal stuff. Im pretty sure she's not paying taxes and that's the reason she doesn't want to sign the document for me. Should I just tell the apartment manager the situation or do I even need their signature if I go through a notary? I just don't want to lose these apartments because I do make the money required to move into the apartments I just need the document. I don't know what to do. Thanks if any one can help me.