Hello. My 3 Year-old Fell Before Halloween And A Small

Hello. My 3 year-old fell before Halloween and a small bruise on her face that turned into a huge abscess. It was treated with oral antibiotics (two different kinds), and has been slowly healing since she finished the medication. However, all this time later, she still has a red mark covering a large part of her cheek and residual firmness under the skin that, while smaller than the original abscess, has not gotten smaller in several weeks. Is it normal for an abscess to take this long to heal, or should I be concerned?