Family in DIRE need of vehicle

Things have certainly went downhill lately. My car took its last ride last week. Not worth fixing. After that I lost my job, our family's main source of income. I'm suspended until I get another one.. my job requires one (home health aid) my husband works but it ddoesn't pay the bills. To make matters worst Christmas is right around the corner. I can't even buy my children gifts! I met a very nice lady who has a very reliable car she is willing to sell me. She wants 2000 but said if I can get 700 down we can file her as a lein holder and I can pay payments. I've tried everything. I can't get apprived for anything because last time things got tough my credit suffered I have been trying to repair it. I don't really know what to do at this point but hope and pray. This opportunity is huge. I'm praying someone out their somewhere can help me. If anyone helped me I would have no issue providing proof of purchase. I'm sick to my stomach. The quicker I get a vehicle the quicker I can go back to work!