This answer is not intended to provide you with specific legal advice regarding your situation, and it is not intended to create any attorney-client relationship.
I assume that there are not specific provisions in the Will or any related document stating that certain items of tangible personal property are to be distributed to specific people. If there are, then you will need to follow those provisions.
For any tangible personal property which is not specifically to be distributed to named people, then you should first look at the provisions of the Will to see whether you, as the Executor, have the power to sell or otherwise dispose of tangible personal property items without the consent of the beneficiaries. If the Will allows the Executor to sell or dispose of items of tangible personal property, then you may have some ability to sell as much of the tangible personal property as you can, and distribute the proceeds to the beneficiaries (the beneficiaries of the tangible personal property, and the shares they should receive, should also be stated in the Will If the Will does not specifically give you this power, then your ability to act may be more limited, and you may actually need to seek court approval for a proposed distribution of the tangible personal property, especially if your sisters (and any other beneficiaries) won't co-operate with you. Most likely, you could not simply give your sisters a deadline on deciding how to dispose of the property and then, if they don't meet that deadline, distribute the property in any way you please.
If you have not hired an attorney to help you with the estate administration, you may want to consider doing so. One thing to keep in mind, as Executor, is that you are subject to a duty to act in good faith, and that you generally cannot simply take actions which may help move the estate administration forward. You have to comply with the Will, with the law, and with the intent of your mother in mind. You must take your duties as the Executor very seriously, and if you have a question regarding what you can do with regard to the estate, the advice of a good lawyer can be very beneficial. Also, if you have relied on legal advice in deciding how to proceed on a certain estate administration issue, you may be better protected from attack by an unhappy beneficiary who wants to complain about an action you did take.