"Those are my sisters"

Translation: Wale ni dada zangu

[AGreatUserName]

For anybody wondering why it's zangu not wangu, although this is an animate noun, in class 9/10 (the N class) the possessive / genitive / associative / whateveryouwanttocallthemative words (-a, -angu, -ako etc.) do not take the concords of the 1/2 (M-WA) class.

I suppose this is because the 1/2 class doesn't indicate plural with those.

mume wangu
waume wangu

Because 9/10 nouns don't indicate plural or singular directly, they are given every chance they can get to show this, so instead of wa for both singular and plural, they are used with ya for singular and za for plural just like inanimate nouns.

dada yangu
dada zangu

All the other concords follow 1/2 though.

Dada yangu mkubwa analala.
= My older sister is sleeping.

Dada zangu wakubwa wanalala.
= My older sisters are sleeping.

[aboutpurpo]

Thanks. I definitely did not know that and naturally gave it the animate prefix

[AGreatUserName]

After having learnt more: this tends to be done only with kinship terms and other regularly possessed words such as rafiki. With animals, it's done most frequently in plural, but singular not so much: ng'ombe wangu > ng'ombe zangu, but some people don't do it at all. There's a lot of variation. In some areas people use the noun classes strictly, ignoring the rules about animacy entirely.

[Catriona28475]

But there seems to be a debate about whether dada actually is class 9/10 (N) or 5/6 (JI/MA), as in many dictionaries.

[Gazelle1596]

I have seen most dictionaries list it as both. :)
And as AGreatUserName pointed out, there is regional variety - you will find both. :)