Is it possible once my wife becomes a US citizen to file the I130 concurrently with the I485 while her mother is visiting us?

It is possible for a US citizen to sponsor their parent.

Generally, a U.S. citizen (whether by birth or through naturalization) may sponsor a parent who entered the U.S. lawfully and with inspection, to become a Lawful Permanent Resident (to get a "Green Card") by concurrently filing I-130 and I-485 application. If the foreign national parent entered the U.S. with a visitor's visa, be aware that that this type of visa requires "nonimmigrant intent," i.e. an intention to enter the U.S. to visit temporarily and then to depart; it would be impermissible, and could be viewed as constituting visa fraud, for someone to enter the U.S. with a visitor's visa while intended to apply to become a Permanent Resident. Of course, a foreign national legitimately could enter the U.S. intending to stay temporarily, and then change his/her mind and decide to apply to remain permanently, and filing an adjustment of status application package more than sixty days following entry can help establish that an entry legitimately was made with nonimmigrant intent and that the foreign national later changed his/her mind. "Consular processing" from abroad is an alternative to this approach. There are many other issues that can have an impact upon eligibility, and this includes any perceived misuse of a prior visa, although in answer to your question the I-94 defines the period of time a person is authorized to remain in the U.S. during each visit. It would be wise for your family to consult with an immigration attorney not only in connection with immigration considerations for your wife's mother, but also in connection with the upcoming I-175 and N-400 application processes. Failure to properly prepare and fully document those applications can lead to very significant delays (or even more harsh consequences).