Young girls? really? Any human being with the use of reason would not make such a connection when browsing an adult website. If you are browsing or using adult content and automatically associate the word girl with young girl; the perversion is on you, plain and simple. Or you are not fluent enough in English, I cannot think of any other reasons. (Does anyone know what context means anymore?)

If replacing it with 'model' benefits the presentation of the product business-wise, then fine, change it; But it is one thing to say it is unprofessional and another is to make ridiculous connections.

Reminds me of George Carlin's critique on soft language:
Partly cloudy became partly sunny, room service became guest room dining, poor people are not broke, they have a negative cash flow, you are not 90 years old, instead you are 90 years young...