Thank you for the additional photos - I will need a few more photos of the marks in the back of the dolls head as well as a picture of the entire doll where it is laid out flat.
Thank you.

Thank you for contacting Mearto with your appraisal inquiry.

It is a cute doll. However after having examined the photos very carefully we have come to the conclusion that it is not an antique Kestner porcelain doll. The way the dolls face is modelled and the colours of the paint in the face are not the way antique dolls were made and painted. The body and the way that this appears from the photos also indicated that it is a copy of an antique doll.
During the late 1900s there were made several artist dolls by various dollmakers. These dolls have collector

The sentimental value it represents to you will be much higher than the market value.
I am very sorry for the unfortunate news. 
Please let me know if you have any additional questions. I’m happy to help. 
Thank you