A referral can come from anybody, realtors from other cities or states, even satisfied past clients. There is paperwork associated with sending someone a referral, if two realtors are involved so that the other agent gets paid a portion of commission.
It is unlikely that an agent in Beverly's office would have given Beverly a referral, unless perhaps he/she did not specialize in homes. A commercial agent, for example, wouldn't know residential real estate as well and wouldn't be comfortable or knowledgeable.
A realtor from another city or state or province would need someone competent, like Beverly, that wouldn't lose the business. Sometimes you have to be the buying couple's best friend for the time they are in town, so they don't stray. Referrals are always appreciated and agents tend to treat those people very well. Agents always love referrals, ... the hardest thing in real estate is finding the clients.
Do we know for sure that it was a referral, or was that what Beverly's husband thought she said?
That part does make me go hmmmm.