No,we were asked 48,000*3= 144,000 for the outbound and 288,000 for the round tripe i.e. 96,000 for each.
My question was, is it normal that the baby has to pay 96,000 miles as well cause she doesn't even have her own seat!

Anyway, I called three time this morning and I have the answer: NO.

Beware of the ignorant AF agent:
- First time I called, two days ago, the lady told me 48,000 miles per leg, per person including the baby. I asked her twice if she is sure that the baby has to pay with miles, she said yes.
- Second attempt this morning, I was told 40,000 for the entire trip for each of us i.e. 120,000 miles grand total,but she told me that there is no seat available for the moment, to try again in a few days.

Then I discovered this forum and followed a link to the FB website which allows me to calculate the exact amount of miles and I got 30,000 miles for me and 15,000 miles for my husband (I have an A fare ticket and he has an S fare), so 45,000 for one way.

- So I called a third time, but this time the guy told me that it was 60,000 for each of us just for the CDG-NY leg (180,000 miles for the three of us).
I told him that there is no way it's that many I saw the table on the website and it states 45,000 and the baby is not included.
He seemed confused and asked to let him double check and get back to me. He came back 3mins later and told me that he is going to forward me to a king of upgrade specialist.
And then, I talked to the most profesionnal and helpful agent, who clearly explained to me that the baby does NOT need miles to upgrade, she'll just change her ticket to a business class ticket and I paid a few euros for the baby J ticket to be issued.
Long story short there were no J available for miles upgrade for CDG-NY but we did upgrade from NY to CDG for 45,000 miles (30,000 for my A fare ticket and 15,000 for my husband's S fare ticket).

Bottom line is, always double check with the miles calculator before and don't hesitate to tell them what you have on the website if they quote a different amount. I went from 144,000 miles to 40,000 to 180,000 and ended up using only 45,000.