Character mistake: At the end of the episode when Maria is framed for the prison panty business and told to expect an additional 3-5 years on her sentence she cries saying that her daughter Pepa will be in kindergarten by the time she gets out. However in season 2 episode 12 Maria tells Piper that she still has 6 years left on her sentence. This means that even without the extended sentence her baby would have been well past kindergarten age by the time she was released, so taking the extra 3-5 years into account, Pepa could be almost finished in elementary school by the time her mother got out of prison.
Factual error: Whenever Tiffany gets her dentures there's one problem. She's got her hands cuffed in front and prisoners, unless they're cuffed to the waist and ankles too, should have her hands cuffed behind her back.
Full Bush, Half Snickers - S5-E7
Continuity mistake: When Red and Flores are texting Piscatella to come into the prison from Humps' phone, in one of the texts, Humps says "Thx" and Piscatella texts "Np". The time Red and Flores send is 4:59 and the text is sent from iMessage. When Piscatella checks his phone the time is 4:56, the messages were sent by the opposite people, and it's an Android phone, incompatible with iMessage. (00:53:03)
Continuity mistake: During episode 6-3, it is established that all inmates at the Ohio prison facility are required to have their hair cut in order to prevent the spreading of lice. Later on in the series, it is revealed that almost all of the inmates that were not moved to Litchfield Max after the riot were sent to Ohio. Despite that, several of the inmates formerly from Litchfield were shown still having long hair in scenes that took place in the Ohio facility, and Maritza's hair was long when she first appeared at the nightclub while she was on parole. While it is possible that the policy may have been rescinded between the events of seasons six and seven (which would explain why Alex's hair was still long when Piper visited her), that does not explain the other characters that were immediately transferred to Ohio still having their hair long during subsequent appearances.
Character mistake: The zip tie handcuffs on the arrested inmates were not tightened. (00:25:18)
Other mistake: The subtitles refer to the men cheering for the female soldier that was stripping as "Marines" despite all of them being in the Army. (00:24:10)
Plot hole: "Red" is somehow serving a life term or what for the execution murders of some Russian spies, her husband and his cronies had headed up. But her hubby somehow escaped any such sentencing.
Answer: You would need to be more specific as to which inmate to get an answer as to who possibly belongs in the mental ward. In general; usually the only mentally ill prisoners who go to the mental ward are inmates who show obvious psychotic breaks like Loli and crazy eyes as, with the conditions of prison, it's often difficult to tell who is mentally ill and whose frustrated from the conditions. Many of them are also only there temporarily. Crazy Eyes, first example, was in the mental ward. Her mother fought and won to get her out.