Internet sharing since you need to assign some more from principal to the 2 supplementaries that otherwise need 30GB.
This, you'll be stuck with 2 supplementaries having large unshareable quota.
Principal 25GB/RM60
+ 2× Family 10GB/RM20
+ 2× Family 25GB/RM30
+ Internet Sharing  RM10 (assign additional 5GB to suppl)
= RM170

This, you'll have flexibility to adjust quota assignment as need be.
Principal 50GB/RM90
+ 4× Family 10GB/RM20
+ Internet Sharing  RM10 (assign additional 20GB to suppl).
= RM180

This, you buy data add-on.
Principal 10GB/RM40
+ 4× Family 10GB/RM20
+ 4× add-on 10GB/30d/RM10
+ Internet Sharing  RM10 (assign additional 20GB to suppl)
= RM170
if you chose prepaid, make sure you only consider those long-term add-on offer only, not seasonal promo add-on. else later facepalm if you account savings based on seasonal.
* Family 40 requires minimum Postpaid 40.
Family 60 requires minimum Postpaid 60.
Family 90 requires minimum Postpaid 90.