The Oxandrolone hormone does not carry any estrogenic related side effects. It does not aromatize and cannot lead to gynecomastia or water retention due to increases in estrogen levels. It further carries no progestin related activity, which again supports no estrogenic related side effects. Due to water retention being impossible with this steroid, this will decrease the risk of high blood pressure. Excess water retention can promote high blood pressure. Some steroids that do not aromatize can lead to high blood pressure, such as Trenbolone , but Anavar is rarely associated with this trait.
Maybe I'll get downvoted for this, but I don't think women should take ANY kind of AAS unless they are planning on competing in something physique or strength related and fully know and accept the possible (permanent) side effects. There's a reason the second A in AAS stands for "Androgenic". Is it really worth the potentially permanent virilization side effects just so she can look good for one summer? She'll probably lose the majority of her gains once she comes off the var anyway. If her clit gets enlarged or her voice deepens, she won't be losing that ever, though.