It is only complicated because she committed a grave evil in the first place-- IVF and freezing embryos. Children are not commodities. They are not to be pursued by any means.
There is no resolution to the current situation of the frozen embryos. They cannot be implanted and they cacnnot be killed. Embryo adoption is not a licit solution either.
Perhaps her payments to keep her embryonic children alive indefinitely can be viewed as a form of penance for the grave situation she created. Maybe she truly did not know that IVF was wrong to do-- if so, then she may not be culpable for her original decision, but she now is responsible for the lives she created.
Yes, this is a harsh post, but creating children in a lab is a great evil. See this document of the Vatican:
vatican.va/roman_curia/congregations/cfaith/documents/rc_con_cfaith_doc_20081208_dignitas-personae_en.html
From Dignitas Personae:
19. With regard to the large number of frozen embryos already in existence the question becomes: what to do with them? Some of those who pose this question do not grasp its ethical nature, motivated as they are by laws in some countries that require cryopreservation centers to empty their storage tanks periodically.*Others, however, are aware that a grave injustice has been perpetrated and wonder how best to respond to the duty of resolving it.
Proposals to use these embryos for research or for the treatment of disease are obviously unacceptable because they treat the embryos as mere “biological material” and result in their destruction. The proposal to thaw such embryos without reactivating them and use them for research, as if they were normal cadavers, is also unacceptable.[37]
The proposal that these embryos could be put at the disposal of infertile couples as a treatment for infertility is not ethically acceptable for the same reasons which make artificial heterologous procreation illicit as well as any form of surrogate motherhood;[38] this practice would also lead to other problems of a medical, psychological and legal nature.
It has also been proposed, solely in order to allow human beings to be born who are otherwise condemned to destruction, that there could be a form of “prenatal adoption”. This proposal, praiseworthy with regard to the intention of respecting and defending human life, presents however various problems not dissimilar to those mentioned above.
All things considered, it needs to be recognized that the thousands of abandoned embryos represent a situation of injustice which in fact cannot be resolved. Therefore John Paul II made an “appeal to the conscience of the world’s scientific authorities and in particular to doctors, that the production of human embryos be halted, taking into account that
there seems to be no morally licit solution regarding the human destiny of the thousands and thousands of ‘frozen’ embryos which are and remain the subjects of essential rights and should therefore be protected by law as human persons*”.[39]
So, from above, she cannot kill them, she cannot implant them, she cannot give them for adoption. She can only continue to sustain the lives she created.
While certainly the cancer she has undergone and resulting sterility are not her fault and cancer is a terrible thing to have happen to you, that is a separate issue from the IVF issue.