Yes, you can probably be a co-signer on the loan but have you discussed being on the deed? I would recommend you speak with your attorney regarding the best strategy for you.
Another option would be for them to explore different mortgage options with several banks and brokers. There are many programs targeted towards first time buyers or those with less money to put down such as FHA loans. If you want more infomration, feel free to contact me or visit my website at http://www.CTHomeConsultant.com
If you would like some names of loan officers, contact me. I have worked with a few really good ones over the years.