An unpleasent surprise

Late night, Teri, Elena and I were having a quiet dinner. Nastia was at work at the movies. Teri left the table and went up stairs, it was just Elena and I.
  Elena starts scratching her face and rubbing her eyes. I think she is suffering from allergies, so I tell her the more you scratch, the more it will itch. She gets up and goes to the bathroom down stairs. She comes back, then so does Teri.
  Teri looks at her and asks her if something is wrong, Elena says, no, she continues to scratch her face. Again Teri asks her if something is wrong. I get up to clear my plate and I want Teri to quit bugging Elena.
  When I sit back down she is still pushing Elena. I lift up her glasses and look at her face. I see some red cheeks and they are slightly puffy. Teri is still pushing Elena to tell her what is wrong, I still don't see anything really wrong.
  The next thing I hear is Teri, her voice starting to raise a little and a touch of frantic entering it say to her what did you take. I'm thinking, take, our daughter doesn't take anything!
  It turns out Elena had a bad headache, so she goes upstairs to take some aspirin. The problem is She doesn't know what to take, so she guesses and since it is a bad headache, she takes three. When she tells Teri what the bottle looks like and I read oxycodone, I get scared. At that point Elena decides it is time to throw up again and She hustles down stairs, Teri follows, I am asked to call and find out about the medicine she took.
  I call CVS and talk to the pharmacist, a pleasant lady who reassures me that Elena took Percocet and being it was out dated, it was less potent. She also gives me poison control's number, which I call and get another pleasant women who reassures me again that it was not endangering. She says the same things that CVS said and also said her throwing up was good too, it getting some of the drugs out of her system.
Poison Control also said she would feel bad for several hours, head, stomach would hurt, she would feel a little dizzy and keep her hydrated. Give her something to eat.
  Now a day later, she is mostly good, but is complaining her stomach bothers her. Teri say she's like the comment about Barney Rubble in the movie Night Shift, that Barney Rubble, what an actor.
She's acting a little if you don't get the reference.
The thing that bothers me most about this, is I didn't notice the three trips to the bathroom in a short time and the change in Elena's behavior.
The one thing we stressed beside never take medicine you can't read is never take more then two pills, unless told to.