Slaves of to their image at 12 years old

Their age is inside the interval of between 12 and 15 years old (or their age is in the range of 12 to 15 years old). They are starting to use make-up and choose high heeled shoes. They decide to wear clothes to strengthen their sexuality which is not suitable for their age, They are the princesses of the XXI century, who pressed by the expectations of beauty canons, have been transformed into slaves of their image,The experts pointed out that although that issue is not new, it had has spread in the last two years and had has influenced on the youngest girls. The probable cause is the social networks and the proliferation of mobile devices proliferation, which provide sexual stereotypes.
This slavery has its consequences. The girls are too worried about what they others think about hers them which leads to a lack of a properly mental development added to a non-acceptance of theirselves themselves. They have no critical skills and therefore they adopt a submissive attitude especially with males.

Good stuff Lidia, you are so prolific with your notebook entries. As always, my corrections are in red and my suggestions to sound more natural are in blue/grey.

Slaves of their image at 12 years old

Their age is between 12 and 15 years old. They are starting to use make-up and choose high heeled shoes. They decide to wear clothes to strengthen (better: promote) their sexuality which is not suitable for their age, They are the princesses of XXI century, who pressed by the beauty canons who because of social pressure, have been transformed into becoming  slaves to their image,The experts pointed out that although the issue is not new, had spread in the last two years and had influenced on the youngest girls. The probable cause is the proliferation of social networks and mobile devices  which provide sexual stereotypes.
This slavery has its consequences. The girls are too worried about what they others think about them which leads to a lack of a properly mental development promotes a lack of acceptance of themselves. They have no critical skills and therefore they adopt a submissive attitude especially with males.

estoy de acuerdo

Estas mujeres quizás estén bellas pero serán esposas horribles. Ten cuidado, hombres. No serán felices. Claro el mismo problema tienen los hombres aunque se manifesta diferente manera. ten cuidado, senoritas.

Slaves to their image at 12 years old

Their age is inside the interval of 12 and 15 years old(?) They are starting to use make-up and choose high heeled shoes. They decide to wear clothes to strengthen their sexuality which is not suitable for their age. They are the princesses of the XXI century, who pressed by the beauty canons, have transformed into slaves of their image. The experts pointed out that although this issue is not new, it has spread in the last two years and has influenced younger girls. The probable cause is social media and a proliferation of mobile devices which provide sexual stereotypes.
This slavery has its consequences. The girls are too worried about what others will think about them, leading to a lack of proper mental development, as well as an inability to accept themselves. They have no critical skills and therefore they adopt a submissive attitude especially with males.

Slaves of their image at 12 years old

They are between 12 and 15 years old. They are starting to use make-up and choose high heeled shoes. They decide to wear clothes which strengthen their sexuality which is not suitable for their age, They are the princesses of the 21st century, who pressed by the beauty cannons, have transformed into slaves of their image. The experts pointed out that although this issue is not new, it has spread in the last two years and has influenced on the youngest girls. The probable cause is the socialnets and mobile devices proliferation proliferation of the internet and mobile devices, which provide sexual stereotypes.
This slavery has its consequences. The girls are too worried about what they others think about them which leads to a lack of a proper mental development added to a non acceptance of themselves. They have no critical skills and therefore they adopt a submissive attitude, especially with males.