Yes, & upon the death of the person reserving a life estate, the property will be owned by both of the 2 Grantees
I there are other grantees on the deed with you then yes, you are a co-owner.
The person who is receiving the life estate must be listed as grantee in the deed along with the clear intention that only a life estate is granted. The deed should be drafted by a professional who can discuss the consequences and responsibilities associated with granting a life estate.
You may have a problem. You need to consult with an attorney who specializes in real estate law who can review the deed under your state laws and determine if there needs to be any corrective work done.
If your dad conveyed his condo to you by deed and reserved a life estate for himself then he can use and occupy the condo during his natural life. The life estate will be extinguished upon his death or if he relinquishes it to you by a deed of release before then. His wife has no interest in the property.
If your name is on the deed, no. A life estate would serve no purpose as long as they can't sell it without your approval.
A person's name is generally removed by "conveyance" of a new quitclaim deed, signed by all parties to the initial deed, naming the remaining parties as grantees. In case of a death, the decedent's estate representatives would have the power to sign, and the local rules may require registration (or reference to) the probate and death certificate.
The phrasing "and/or" is not used on a deed. That term is used on joint bank accounts. If two people want to own real property jointly the deed must name both as grantees "as joint tenants with the right of survivorship".
The names on the current deed determine who is listed as owner in the tax assessor's records. All the grantees on the deed are responsible for paying the property taxes.
I will assume that the 'grantor' conveyed property to you and reserved a life estate. If that life tenant has died their life estate is extinguished. You need to record a Death Certificate in the land records to show proof of their death. You are now the fee owner and the property is free and clear of the life estate. You can convey the property by any type of deed listing you as the grantor. You could add a statement at the end of the deed stating that the life tenant (name) died on (date) and a Death Certificate is recorded in (recording reference). You could also attach a Death certificate to the deed of conveyance and record both at the same time.
Your mother's estate must be probated in order for title to the real estate to pass to you legally. The attorney who handles the estate can draft a new deed for you once the estate has been probated.
If you mean deed to daughter, with mom reserving a life estate, then mom owns a life estate, remainder to daughter. Mom has the right to live in the house, has the duty to maintain it, has the duty to pay taxes on it. If there's a mortgage, mom has to pay the interest. Daughter has to pay reductions in principal. Neither has the duty to insure it, but if mom insures it, mom gets the proceeds on any policy claim.
A person who has a life estate in the property has the right to the use and possession of the property for the duration of their natural life. You have not explained how the situation came about.