Do their daughters have a share of the inheritance if they have no need of it?

Firstly: 

What is required with regard to dividing the inheritance is to give each person who is entitled to a share his due share. There is no differentiation between rich and poor, male and female; each individual should take the share that Allah has allocated to him. 

It was narrated that Abu Umaamah (may Allah be pleased with him) said: I heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “Allah has granted each one who is entitled to a share his due share, and there is no bequest to an heir.” 

Narrated by Abu Dawood (2870); classed as saheeh by al-Albaani in Saheeh Abi Dawood

This is a confirmation of the words of Allah (interpretation of the meaning):

“Allah commands you as regards your children’s (inheritance); to the male, a portion equal to that of two females; if (there are) only daughters, two or more, their share is two thirds of the inheritance; if only one, her share is half”

[an-Nisa’ 4:11]. 

Then Allah warns those who go against His division of the inheritance and tamper with it, as He says (interpretation of the meaning):

“And whosoever disobeys Allah and His Messenger (Muhammad SAW), and transgresses His limits, He will cast him into the Fire, to abide therein; and he shall have a disgraceful torment”

[an-Nisa’ 4:14]. 

Shaykh Ibn Baaz (may Allah have mercy on him) said: It is not permissible for anyone to deprive a woman of her inheritance or to use tricks to do so because Allah, may He be glorified, has allocated a share of inheritance to her in His holy Book and in the Sunnah of His Messenger (blessings and peace of Allah be upon him). And the Muslim scholars are unanimously agreed on that. Allah, may He be exalted, says (interpretation of the meaning):

“Allah commands you as regards your childrens (inheritance); to the male, a portion equal to that of two females; if (there are) only daughters, two or more, their share is two thirds of the inheritance; if only one, her share is half. For parents, a sixth share of inheritance to each if the deceased left children; if no children, and the parents are the (only) heirs, the mother has a third; if the deceased left brothers or (sisters), the mother has a sixth…”

[an-Nisa’ 4:11]. 

What all Muslims must do is act in accordance with the laws of Allah with regard to inheritance and other matters, and beware of that which is contrary to that; they should denounce anyone who denies the laws of Allah or uses tricks to go against them and deprive women of inheritance or other acts that are contrary to sharee‘ah. 

These people who deprive women of inheritance or use tricks to do so, in addition to going against sharee‘ah and the consensus of the Muslim scholars, are also following in the footsteps of the kuffaar by doing ignorant deeds that deprive women of inheritance.

End quote from Majmoo‘ al-Fataawa, 20/221 

If there is no other heir but you, then the estate be divided among you, with each male getting the share of two females. So the estate should be divided into eleven shares, because there are three males whose shares are equivalent to those of six females. Then each male should take two shares and each female should take one share. 

And Allah knows best.