A customer was trying to deposit a check made payable to: Jane Doe Life Est

This will be a royalty check from her fathers mineral rights to be received monthly. Her account with us is a joint account with her husband.

Does she need to setup a separate account for the "Life Est" or can it be deposited directly to her existing account?
If yes, can she have a beneficiary or a co-owner?

No, the check is not made payble to either her or her husband. I assume "Life Est" means life estate. Does she have the authority to open an account would depend on the estate.

So a separate account would need to be established and the documents giving her the authority would be needed. If yes, could she have a POD or would it automatically go to her estate?

Any kind of estate account is an entity. Entities do not die so in the event of her passing, the court that ordered the creation of the estate would have to appoint a new fiduciary or if this is trust relationship, the trust documents should name a successor. There would be no POD on this type of account.

I'll gently dissent...

As you describe it the woman has a "life estate" in the mineral rights. That means that when she dies, someone else, the remainderman, will be entitled to the payments. The problem here is that there is simply no reason to put "life estate" or "remainderman" on the check, both describe a period of time, not a form of ownership.

In my opinion, the term is surplusage and has no effect. Find out what your attorney thinks.

I am with Ken on this. That legend is an artifact of the asset from which the payment is derived. The intent of the check issuer is that she get the money if she is alive. And the word "estate," while often associated with the assets left behind when one dies, can have a much broader legal meaning.