(Note: unless you know someone very well, or have some very good reason for asking, it can be considered very rude to ask questions about how or whether they are breastfeeding.) "Is the baby still breastfeeding, or has he/she been weaned?" "Have you weaned the baby off of breastmilk?" also works

Than you so much for the effort to answer the question.

Oh! In that case Muhammed to ask your wife if she has finished feeding the baby for that particular time you can ask: “Has he/she/the baby finished feeding?”

Actually I was to ask this question to my wife and my intention is to ask if the session for which she was feeding was finished or not, I didn't mean discontinuation(in the sense of weaning) of breastfeeding. Please suggest a good sentence in the context of that particular session.

Yes, Muhammed you can ask “Is the baby still breastfeeding or has it stopped?” You can also ask “Is the baby still breast fed?” Your first sentence is the best but you don’t need to add “or has it stopped” if you don’t want to. You can also ask “Has the baby been weaned yet?” To be weaned means to stop breastfeeding. Hope that helps. Alice