|There are no more "new" VCRs, there are still "a few" DVD/VCR combos like your grandmother has, but nobody is making or selling VCRs anymore. They've about gone the way of the 8-track.|
You would need to provide the specifications (make/model) of your grandmother's DVD/VCR combo and describe what exactly she wants to do with it before anyone on this forum can be any real help (as in providing simple instructions you could pass to your grandmother).
What does having a "new flat screen" TV have to do with recording on a VCR? I have a "new flat screen" TV which is really nice for PLAYING back video from the VCR, but it doesn't make a bit of difference as far as recording to the VCR. The VCR doesn't record one bit better with the new TV than it did with the 25-year old TV that was replaced. Your grandmothers new TV doesn't do anything to help her record to her VCR.