Summing up:
1. She was the only child that returned positive. The other 4 tested negative at cut-off.
2. Heavy cocaine contamination can lead to freakishly high results, but surely it would mean everyone gets contaminated equally, more or less.
3. We know this was Nicholas Rekieta's favourite, we know the cocaine was stored in the master's bedroom. We also know the Qover slept there.
Therefore, either she was in the same room with prolonged exposure to cocaine, its usage and drug paraphernalia (they were out in the open according to the court documents) with the Qover sleeping, or somehow she ingested the drug.
One scenario could be explained as a false positive assuming >5000pg/mg was the drug itself, the other suggests it was not.
Or both could be true.
He allowed it to happen in the first place. He brought in the drugs, he brought in the slatternly crackwhore and her stupid ex-husband. They did drugs in the master bedroom.