All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
First of all, you should know that the future of your daughter, and your future, and the future of all the people depends on the obedience of Allaah. Therefore, the prayer should be the first priority in a Muslim's life, and so, he should be concerned about his prayer more than being concerned about his studies.
Secondly, we have already issued Fatwa 92109 on the ruling of praying at home where a dog is kept, so you should refer to it.
Furthermore, it is not permissible for a person to perform the prayer sitting while he is able to perform it while standing. Therefore, your daughter is obliged to perform the prayer while in the standing position.
As regards praying in that house, the scholars stated that if a person doubts the purity of a place but he is not sure that it is impure, then his prayer there is valid.
Ash-Shaafi'ee said: "If a man is sure that a given spot on the ground is touched by some impurity, then I prefer that he changes the place and goes to another place where he does not doubt its purity. However, if he does not do so, it is acceptable for him to pray [his prayer is valid] in any place if he is sure that it is not touched by impurity. Similarly, if one prays in a given place and then doubts whether or not it is touched by impurity, then his prayer is valid, and in principle, the earth is pure unless one is certain that it is touched by impurity."
Therefore, if your daughter does not arrive home except after the time of the Maghrib prayer is finished, then she should endeavour to perform the prayer where she is. If it is necessary for her to take a prayer mat or a cloth on which she may perform the prayer, then she must do so. We do not think that this is a burden for her. However, if she arrives home before the end of the time of the Maghrib prayer, then in this case it is permissible for her to delay the prayer until she arrives home.
Allaah Knows best.