Is being pregnant (natural) with twins at 42 unexpected?

My aunt and uncle really thought they weren't going to have anymore kids. She's now 7 months pregnant with twins.

She didn't even had any treatment at all. She was in shock that she could still get pregnant. Is that totally unexpected? To not just get still get pregnant at that age but with twins?

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This took both of them by surprise.
Is being pregnant (natural) with twins at 42 unexpected?
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