I am sorry that you are feeling a little depressed about this..........I'm sure you're doing everything to soothe your new daughter. She is just a different baby than your son.
The important thing is taking care of YOU during this difficult time. A "happy mom" can usually equal a "happy home". It does sound like you might be fighting the emotions of Post Partum......very natural, very common.
Do your best to get up every morning and get dressed.....with makeup....even if you're not going anywhere. Nap (when possible) with your children and FORGET about all the things that have to be done in the house while you're napping. This is eaiser said than done, but you have to try.
Explain to your hubby what you're going through so he tries to be patient with your changes towards taking care of yourself. He may even "pitch in" a little more to help you ease your stress.
When anyone offers to do ANYTHING for you (no matter how small of a task)....say YES and thank you. The more help you get the quicker you will get through this. It is difficult to let others help us......as mom's, we feel like we have to "do it all" in order to feel as though we a being a good mom.....but throw that theory out the window for a few weeks and focus on you.......and try to do it without guilt.
As soon as you begin to feel better, you'll feel fresher and ready to handle your new little girl eaiser.
Babies don't always smile right away, and that is very normal. You're probalby just feeling overwhelmed with some P. so you automatically think it's you as a "mother". It's not, though.
Take Care, and keep reaching out if you need encouragment. This, too, will pass.
Blessings!
~N. :o)