If a woman has missed many fasts over several years due to repeated pregnancy and breastfeeding, and she is currently unable to make up the fasts due to health or capacity

Then:

1. She may feed one poor person for each missed day
2. Qada is not required, unless she later becomes able to fast

To get a correct ruling:

1. First, consult a trusted, qualified Islamic scholar, or shaykh, for guidance specific to your circumstances

Islam does not burden a person beyond their ability.