The short answer to your question is no, there is no way for your income to be attributed to your girlfriend if she applies for a mortgage. When you apply for a mortgage, lenders require that borrowers verify their employment and income with documents such as pay stubs, W-2s and tax returns. The income documentation must be in the name of a borrower for the lender to include that income in a mortgage application. In your case, even though your paychecks are deposited directly into your girlfriend's bank account, because your name is on the paycheck and not hers, you are required to be a co-borrower (which means your name appears on the loan documents) for that income to be counted when you apply for a mortgage.
You may be able to find a lender that offers a no documentation mortgage where you are not required to verify your income but these programs are relatively challenging to find. No documentation mortgages also typically impose more challenging borrower qualification requirements such as lower loan-to-value (LTV) ratio limits. Additionally, the mortgage rate on a no documentation mortgage is typically 2.5% - 3.5% higher than a standard mortgage and the closing costs are also higher.
No documentation mortgage are typically provide by specialized mortgage banks or private money lenders. Private money lenders, also referred to as hard money lenders, provide loans that traditional mortgage lenders do not but charge a much higher interest rate and closing costs than traditional lenders. We provide a comprehensive overview of hard money mortgages as well as Six Things You Should Know About a Hard Money Mortgage on FREEandCLEAR. If you do apply for a mortgage with a hard money lender be sure to fully understand the higher interest rate, costs and fees, including any pre-payment penalty, charged by the hard lender.