Are you referring to this female head in VV5? If so, she's the 22nd head in the "Heads chart" so you'd have a better chance of getting her if her parents were heads 21 and 23 respectively (one parent be a head above her on the chart and the other parent below her on the chart), assuming that the genetics works the same as it does in VF.

The "Heads chart" is in your games Image Folder and named bigheads00.png and bigheads10.png. If you are unsure of how to find your games Image folder, there are instructions here for both PC and Mac.

I hope this helps answer your question.