cord blood banking info

We are adopting our niece and considering banking her cord blood. She has a blood half-brother, and will most likely have other blood half-siblings in the future. There is currently no dire need for any of her birth family members to use her stem cells, and we're not sure if half-siblings would benefit as much as full siblings from her cord blood. If there doesn't seem to be much likelihood of need within the family, we will donate her cord blood to a public bank. Any thoughts on who can benefit from one's cord blood? Thank you!