Answered by Ustadh Shuaib Ally
Question: As-salāmu ‘aleykum,
Can I call others of the opposite gender to Islam?
Answer: Yes, you can call others of the opposite gender to Islam.
You should at the same time keep in mind general guidelines related to what is considered appropriate interaction between the genders.
Please see this: A Reader On Gender Interaction
With that in mind, do what is good, and stay away from anything that falls outside the scope of your work, or does not sit well with you.
May Allah reward you for your effort and bless your work.