She had just had a full medical checkup at the hospital yesterday, how could she not know if someone was being resuscitated in her own hospital? Especially for something like poisoning.
Since she didn't know, then it must've been someone falsifying information.
On the way back, she asked her eldest son to look into it, and sure enough, he found that there were doctors in the hospital who had colluded with others, all to frame the Ruan Family. However, they probably didn't expect that their scheme would be discovered and foiled by the old lady as soon as it was executed.
After uncovering the truth, they were certain the Ruan Family would come to the hospital to find out what happened, so following the old lady's request, they prepared the evidence and waited for their arrival.
