In my WIP, my heroine Angel has a best friend, her assistant Ramona. Ramona is blunt and sassy, smart and supportive. She is outgoing and looking for Mr. Right. She corners Angel into agreeing to a first date with the hero, and renegs on her promise to extricate Angel on a pre-arranged signal--exactly what friends are for. She serves as confident and comic relief. I adore her!
In a pending romance, my heroine has no best friend. She is emotionally wounded, a loner, and has to reach out to barmaids and debutantes to get the assistance she needs to reclaim the hero after rejecting his love.
So, I think it depends on the heroine's journey.