First of all, do you know why she is thin? Has she always been so thin, or has she experienced something unexpected?

Because sometimes a person may be thinner. If she is weak, you can advise her to do sports and dance, or you can often take her to run, play badminton and practice yoga. Some simple and not very tired exercise is ok, on the one hand, it can improve her immunity and physical fitness, on the other hand, it can also enhance your feelings. If you eat, you can often cook some chicken soup to drink. If it is a tonic, it is recommended that chicken soup is still quite good, and fish head soup is also ok. You can also drink some red dates, water, brown sugar and ginger tea to supplement your blood. If possible, you'd better exercise, because the more you eat, the better. It depends on whether she can absorb it.