Mateen Charbonneau

You should not abandon hope for her. Continue to encourage her, while not being forceful or pushy. Pray where she sees you and perhaps she will feel remorse that she is not praying. 

A scholar in Najaf told me about being persistent, "I remember there was one of the youth who followed my father in taqlid and at some point he became a communist and left Islam. My father would pass by this youths shop on his way to salat everyday. My father would always say salam to the youth, but the young man would ignore him and never reply. My father kept saying salam to him everyday for one year then the youth finally replied to his salam and ended up repenting and coming back to Islam."

In the book Aqaed al-Haqqa by Ayatullah Sayed Ali Sadr we find infallibility categorized into 3 levels:

1. Ismat ul Kubra which is reserved for the 14 Infallibles. They do not commit sins, mistakes or even tark al-awla (choosing the less preferred method). We as Shia however do not believe that any of the prophets, from their birth until their death, committed any sins at all whether big or small. We see that the honorable Shia scholar, Sheikh Mufid stated that the prophets and Imams never committed sins or even left the recommended actions (mustahab) and that they were perfect in every aspect of their lives.

Another point to bring is that the prophets are not infallible by force. Rather, they are infallible by utilizing their intellectual ability to not succumb to sin. They have the ability to sin, but they choose not to sin. They know the effects and evil disgusting nature of sin and are repulsed by it. An example would be, if we saw an old piece of food that was rotten would we eat that food? Of course not! It is repulsive to us because we see its rottenness. This is how the prophets see sin. They see the rottenness in disobeying God, whereas most of mankind is attracted to the sins because they have been made fair-seeming to them.

2. Ismat ul-Ithbaatiya which is for the general prophets where they do not commit sins, but it is possible for them to do tark al-awla (choosing the less preferred method).

3. Ismat ul- Thubutiya which is an acquired level of infallibility by abandoning sins and continuously doing their responsibilities to Allah and are obedient to Him. They are just individuals and are far away from deviation. We find this type of acquired infallibility in some of the progeny of the infallibles such as Zaynab, Abbas and Masuma (as) and others. 

It is not forbidden

If you urinated before the ghusl, then no further ghusl is required in this case. 

There is also reward in reading the translation. 

"…Said those who prevailed in the matter, "We will surely take [for ourselves] over them a masjid." Quran 18:21

We can understand from this ayah, about the people of the cave, the permissibility of building masajid at burial sights of respected individuals.

Also, refer to Kamil al Ziyarat for many narrations about the significance of visiting Imam Hussain's (as) shrine.

Atheism is denial of Allah as the Creator, while shirk is associating partners with the Creator. 

The best thing for you to do in this situation to safeguard yourself is to introduce her to a knowledgeable Muslim sister who can help her.

We should strive to maintain our family relationships and not break them off. 

We do know that when the believers were exiled into the valley of Abu Talib (as) that Khadija (sa) was not able to do trade with others due to the sanctions placed upon the Muslims.

This is unfounded as for starters you are not telling Allah to say, rather this is Allah's words addressed to the Holy Prophet (s) and the believers. It is highly recommended to say surah ikhlas in prayer and it is disliked to abandon this surah for a whole day. 

A good sermon to read regarding this is the 1st sermon of Nahjul Balagha