You are making progress and I hope you are able to carry all you have learnt forward to your future figures as well.

Does she look adult?  Not to me I am afraid.  Her body could be but the face is certainly a young face, not saying this is bad but not adult.  Age is difficult to portray and, as others have said, there is little demand for V4 characters after the mid twenties.  As far as the age is concerned the shape of the face is important as are the textures. Faces change as they age as does skin textures and it is something we are very aware of in our day to day life.

My personal view is that she would be difficult to age, her face is a young face and there is not enough detail in the skin texture portray anyone much older.

That said, I am not a vendor and, from your early description your original intention was not an adult figure, if it was I suspect you would have progressed differently. 

 

 

I use Poser 13 on Windows 11 - For Scene set up I use a Geekcom A5 -  Ryzen 9 5900HX, with 64 gig ram and 3 TB  storage, mini PC with final rendering done on normal sized desktop using an AMD Ryzen Threadipper 1950X CPU, Corsair Hydro H100i CPU cooler, 3XS EVGA GTX 1080i SC with 11g Ram, 4 X 16gig Corsair DDR4 Ram and a Corsair RM 100 PSU .   The desktop is in a remote location with rendering done via Queue Manager which gives me a clearer desktop and quieter computer room.