Dd is only 3 months and I already want another. Always have wanted at least 2 if not 3 children.
If someone told you that you would have gone through all that I have your dd knowing her now you would have done it for sure- you would do anything for her.
As for the whole breastfeeding situation - you give each of your children the best that you can at the time. With your dd you tried your best and have her 3 long months of the liquid gold... If breastfeeding is more successful the 2nd time around that would be great wouldn't it?! Also since you also have experience at breastfeeding/pumping I would think it would go better anyway.
I am sure your dd would want a sibling... I also think and feel like another poster said that your heart just grows with each child.
2 years from now I bet you will have a new baby and you will be so happy that you did and just as you can't imagine your life without your dd it will be the same about your new baby.
Don't worry about having a favorite. Just anytime you have that feeling in your head immediately replace that thought with "I love each of my children equally"
Good luck with your decision. I feel like you would never regret having another sweet child only regret not having one.
Hugs mama it is a big decision