No, it is not right to use a saviour sibling because they would be put through a lot of surgery with no health benefits for them, in fact, it could have the opposite effect. For example, if they have a kidney removed they would have to be careful for the rest of their life to protect it. Also if the saviour sibling did not succeed in saving their sibling it would have an effect on their mental health and stability.
For the given argument I wish to clarify that the validity of an objective ethical characterization is conditional to the exclusion of religious reference or association. Evidently you lack sufficient knowledge of the issue addressed, In Vitro Fertilization (IVF) does not accompany health defficiencies and provides treatment to the patient by stem cell transplantation, which does not consequent further surgical procedures to follow.
In response to your statement, "Also if the saviour sibling did not succeed in saving their sibling it would have an effect on their mental health and stability", such situations described do not occur due to a proccess known as pre-implantation genetic diagnosis (PGD), in which an embryo's genetic compatibility is identified in accordance to the patients diagnosed disease .
In conclusion the patient is benefited and treated without any damage caused such as "kidney removal". I sincerely advise you to review the subject of your debate before engaging in future arguments.