Since I have been paying for them and have had them on my possession for over a year, can I still be implicated in the sale of stolen goods?
The specific charge MIGHT be "conversion".
The "victim" could sue you in civil court in Florida, as this FL licensed attorney explains:
The tort of conversion is defined as the wrongful deprivation of someone else's property. It is an act of dominion wrongfully asserted over someone else's property inconsistent with his ownership interest. The essence of a conversion claim is not the attainment of the property by the wrongdoer but rather the wrongful denial of that property by another.
The tort of conversion generally occurs where a person wrongfully refuses to relinquish property to which someone else has the right of possession and it can be established despite evidence that the defendant took or retained property based upon his mistaken belief that he had a right to possession, since malice is not a critical element of the action. To state a claim for conversion, a plaintiff must allege facts sufficient to show ownership of the property together with facts that the other party wrongfully asserted dominion over that property. The correct measure of damages in a conversion action is the fair market value of the property at the time of the conversion occurred plus legal interest up through the date of judgment. The damages for conversion are not based on replacement value.
Conversion has been found in instances where:
The wrongful use funds earmarked for a specific purpose with an express instruction that the funds be used for no other purpose.
A beneficiary to a savings account refusal to return funds to a joint tenant from a separate account upon the request of said joint tenant was an exercise of dominion over the funds inconsistent with the joint tenant's right to possess them.
Business partnership funds that were converted for personal use by the defendant.
Statute of Limitations
The statute of limitations on a claim for conversion is four years. The period begins to run when the last element constituting the claim occurs. A defense based on the statute of limitations is typically an affirmative defense which should be plead in an answer. This defense can also be set forth in a motion to dismiss if it appears on the "face of a prior pleading."
Does the saying possession is 9/10 of the law apply?
No.
since I've been paying for them are they considered hers still?
The items were bought using HER credit.
You pawned (as in sold) her property, absent her WRITTEN permission.
If you enjoy your freedom, I suggest you pay off the pawn shop, retrieve the items, and return them to her immediately.
If you do return the items to her, make sure you get a receipt.
If you do nothing, and she is angry, prepare to reap what you have foolishly sown.