Dear Priya,
Whatever reply you give, the interpretation will depend on the mindset of the interviewer.
If an HR Manager takes your interview, he/she might become happy as it may be perceived by him/her that though the candidate has an opportunity to assist her husband, she is choosing to grow in the field of HR. The candidate wishes to match her career growth with her qualification and it is a tribute to the HR fraternity as a whole. He might become happy also.
On the contrary, if a hard-nosed businessperson or the MD of the company takes your interview then he/she may perceive that generally, wives assist their husbands in their business. Though the candidate has a great opportunity to do so or to get exposure in other departments, she is abandoning the opportunity and wishes to grow only in one department. Running one's company requires learning on the go. The interviewer may perceive that the candidate lacks a learning attitude. Hence her decision to stick to one field. Please note that a large number of businesspersons do not place HR professionals at par with their counterparts but a notch below. Amongst them is a tribe that considers HR is nothing but glorified clerks!
The third school of thought could emerge from the mix of the either of the above. The interviewer may think that the candidate could be using their company to widen her exposure in the field of HR. She could use their company for practical training and could quit once she gets sufficient exposure. Therefore, they may consider that candidate is not trustworthy.
Therefore, whatever the reply that you give, how it will be perceived that cannot be predicted. In what direction the thought process of the interviewer could go that cannot be anticipated.
These are my thoughts.
My personal opinion is not to quit your company at all. Instead you may enlarge the scope of your work. Start handling operations or business development. Working for oneself is a pleasure. Notwithstanding the higher remuneration that other companies might offer, this pleasure can never be derived by working for someone (that is by becoming an employee)! However, the final decision is yours.
All the best!
Dinesh Divekar