Hey hun! I breastfed DD1 until DD2 was born and a little while after, though I chose that time to wean her (she was just over 2.5 years) because I found it too heavy going. I tried to get DD1 to share and take turns with the boobies but whenever DD2 needed to feed, she demanded to be fed as well so I had them both on at once. That's a good option of course if you're happy to do it but I felt a bit crowded! My Ob also told me that if I was going to breastfeed both of my girls, I had to make sure the newborn was fed first so that my breasts had enough milk for her. Obviously you adjust to however much milk you need to make but this is more while breastfeeding is being established with your little one. Also, some toddlers self-wean while mum is pregnant because the supply drops off and the taste changes. I found that when I was breastfeeding both at once, DD1 put on a little weight because my milk was tailored for my newbie.