It is horrible how people treat their animals. Poor little girl all alone and missing her babies. Sounds like the little one could use some help sooner than later and I am sure you would make a great Meowmie to her. Why not take her and see how things go. You could always consider her a foster until you see how Maya & Inka take to her and see how you do with the added work. I am sure that you have plenty of love to share with all of them, but if it doesn't work out with Maya & Inka at least the little girl has a home until another can be found.