The company has been bought through bankruptsy we are now changing the company name, EIN, etc for the new company. Are we entitled to keep all current employees? One in particular is an older employee who the new company wants her to retire. What is the correct way to handle this situation? She is having health issues right now and is not able to perform her job.

Where would this be located and Is there a Union, and if there is is there a labor contract still in force?

In general.. no they don't have to keep any or all of the old employees. But most will because they have a ready work force that knows the ropes.

If someone can't do their job.. even with a Union... no employer is required to keep them on board assuming they are not out on disability (and then a whole new set of rules apply.

... Are we entitled to keep all current employees? ...

Yes, if they want to work for you, but I am pretty sure you mean to ask whether you must keep them. You would be well advised to seek competent legal advice on this issue; taking advice from an anonymous online source in this instance can result in a costly mistake.

I advise you to find an attorney who knows the difference between "can" and "must"; and how to spell "bankruptcy".

Entitled ? ( no one is really entitled unless there is a contract, and even that may be mute if the firm went bankrupt)

Can, of course the new firm can hire all of the employees. Seldom is this done, since a new company often brings in their own management people.