This is not authentic. However, it is surely advisable to wear long pants under the abayah as this is more conservative and protecting a woman’s leg from being exposed without her knowing it.

I am confused about a muslim woman dressing: Is it must for us to wear trousers under our abya? Icouldnt see any hadith about it but I heard from some people saying “a woman who left her house without wearing trousers under her abaya is cursed by Prophet (saw)”, how much that is true?