Answer
Wa `alaykum As-Salamu waRahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear questioner, we would like to thank you for the great confidence you place in us, and we implore Allah Almighty to help us serve His cause and render our work for His Sake.
Answering your question, Dr. Salah Al-Sawy, President of the Shari`ah Academy and the Secretary General for the Assembly of Muslim Jurists in America, states:
Your work in this field is not void of doubt. This is because these pants show the shape of the `awrah (i.e. parts of the body that must be covered) which violates one of the conditions of clothing for women in the Shari`ah.
We don’t say it is impermissible in the absolute sense because these clothes can be worn inside the homes in front of the husband or mahram(s) or the likes – and isn’t a garment that is only worn in public.
Whoever steers clear of the doubtful has safeguarded his religion and honor; therefore, we say remain in this work so long as you have a need for that, and keep your eyes open in search for an alternative that is purer and more devoid of doubt, allowing your eyes to sleep with relaxation and not a guilty conscience. If Allah eases that for you, then do not seek any alternative besides it, for there is nothing that equates safety in religion! May Allah increase you in cautiousness and success.
Allah Almighty knows best.