YOU SAID:

i think i have roughly ten siblings but only seven guinea pigs

INTO JAPANESE

私は約10人の兄弟がいると思うが、モルモットは7頭しかいない

BACK INTO ENGLISH

I think I have about 10 siblings but only 7 guinea pigs

INTO JAPANESE

私は10人ほどの兄弟がいると思いますが、モルモットはわずか7人です

BACK INTO ENGLISH

I think I have about 10 siblings but only 7 guinea pigs