If TM/SM did not know LE was still looking at them after the first, apparently unofficial search (?) , maybe they decided to get all possible cash together "just in case" they felt LE was honing back in on them. She did make that delusional post about all of the people she was going to sue, just before the arrests, so she may still have felt "safe" at that point. Was it withdrawn right around 12/19, or close to date that LE first approached them? I guess we don't know.
So maybe they were hoarding their cash, checking out possible hiding/escape scenarios, and letting the house go all to h***, in preparation for a late-night skip.
I don't feel like it was a part of the crime, or why would they still have it as of 2/22? (Assuming it was a part of the $10k in house).
JMO