How is the inheritance of a woman who has no heirs except the children of her deceased brother (three daughters and two sons) divided?

If the deceased's heirs are limited to those mentioned, then her estate is for her brother's sons only, because they are 'asabah (agnatic heirs) in themselves and do not make the brother's daughters 'asabah. The brother's daughters have no share in the inheritance. However, it is recommended for the brother's sons to give them something from the estate, as Allah Almighty says: ﴿And when [other] relatives and orphans and the needy are present at the time of division, then provide for them [something] out of it and speak to them words of kindness.﴾ [An-Nisa: 8]. The estate must be divided in Shar'i courts due to issues that might be unknown to the heirs.