Here is what happened last night as I played my first non family rules two player game of Agricola with my wife.
We are at the end of round 4 and the harvest is coming up. She has two family members and turns in 2 food and a grain. She is still short one food and so she decides to take the beggar card. No problem so far.
Now we are at the end of round 7 and another harvest is coming up. She has 2 family members and converts 1 sheep into two food using her fireplace and uses one grain as food and claims "I am done!". I looked at her and said: "but you are still short 1 food!" She said no because the beggar card she took during the first harvest will give her the additional one food she needs.
I looked in the rules and I believe she would have to take another beggar card, however it seems really harsh to get 6 negative points for missing just one food twice during two harvests and the fact that there are only 5 beggar cards that I decided to give her the okay and not make her take another beggar card.