Hi I think dogs are like people . They are socialable with their own kind and get lonesome. Your little girl would probably love a little friend to play with /sleep with etc when you are away and you will feel better too so every body wins.
Financially I believe if you really want something you find a way . At least that is how it has always been with me.
Maybe have to give up something else to get it but it is worth it if your heart is set on it.
The best of luck to you in finding a second little friend for Lillie if that is what is in your heart.
