Hi,
    I understand your concern.
  -  First of all, 6you have to get her fully investigated from a chest physician & know about the extent of her infection.. if it's active  
tuberculosis  passing the infection to others via coughing, 
sneezing )& she needs isolation or  her disease is non infecting & under control.. she can be treated at home & she can feed her baby at this stage.
    Speak to her doctor & decide 
 - Medicines , regular consumption & regular follow up is a must . Tuberculosis can be fully controlled & patient can lead a normal life if she follows treatment plan exactly.
   - Apart from this personsl care in form of-
      - cleanliness,
     - high protein , vitamin, iron ,mineral diet .
         She needs high 
proteins in form of milk 2 glasses in a day , boiled egg/ protein powder available in pharmacy mixed with milk./ fresh vegetables & salads at least 10 glasses of clean water .. apart from her routine meals.
     - light exercises ( yoga/ walking/ respiratory exercises) .. to help  good appetite & digestion
     -Iron & 
vitamins in form of tonics as per doctor's advise.
   Thanks.