She was her husband's victim. She was very unhappy with him. She was relieved when he died in the accident. She felt she could finally be free of him. Apparently, she was in a loveless marriage. So, when her husband came to the house and she learned he hadn't died in the accident, she was devastated to the point of having a heart attack.
Words to describe her: sad, depressed, victim, desperate, overwhelmed, shocked, jubilant
"Pretended" is a past tense verb, so it would be hard to use that as a way to describe her in this situation. "Weird" means that there is something strange about her, but she is just reacting to a terrible situation, even though it turns out to be a good situation in her opinion.