Overstaying visa by two days (two year type)

my daughter was born in china and still has her chinese passport although she is an American citizen through adoption.
She is now in Beijing but has to leave China for Hong Kong to renew three month visa. She was issued a two-year type. I booked a ticket for her to Hong Kong for three months from the day she arrived. The ticket is non-refundable. I didn't realize that would be 92 days. We plan to stay in HK three days, then back to Beijing. Is there a penalty? What will it be? Can she be expelled from China? This was an honest mistake on my part Thank you~