Can/should I file a property lien against a company whose parent corporation filed chapter 11?

Let's start with the general principle that you can not simply "file a lien" under Florida Law except in very specific circumstances. From the facts presented, this does not in any way appear to be one of the exeptions to the general rule.

What you most likely would needed to have done prior to the filing of the bankruptcy was to file a lawsuit for the money owed and to have received a judgment against your former company.

However, it is truly hard to ascertain what needs to be done in this situation without fully reviewing the bankruptcy proceedings and the claim filed on your behalf. Certainly, I do not hold confidence that the company that owned your former company will be your best advocate.

You truly have a situation that would require detailed legal analysis. As it stands now, there is proabably an automatic stay that prevents you from filing an lawsuit against your former company. You probably need to do an analysis as to whether the money owed to you is significant relative to the potential upfront and ongoing investment for legal representation.

If the amount is not that significant, then it is probably best to ride out the Chapter 11 claim pro se. However, at the least you should examine the claim to see if it the amounts stated and the reason owed are correct.

If you can find a lawyer experienced in representing creditors that will provide a consultation for $500 or less, and the amount is $5000 or more owed to you, I would at least get the consultation.

Very challenging situation you have. If you want to add more facts, I would be happy to attempt to improve the helpfulness of my response.