Weird, really. Where were Meng's brothers and relatives?

Meng had a big family. Why Yue was the only person who could take the whole responsibility(Day and night) to take care of his Mom? They all disappeared at this critical time? Even Yue liked to take the reponsibility, but Meng should make use of her at a reasonable level. Even Yue was his wife. No need to mention Yue was not his wife for now. As usual, he naturally forgot about what he should do, mean while naturally care about what can make better off for his Mom, nothing about Yue.