hi
i have dd1 5, ds 2 and dd2 1. dd2 is a clingy breast fed baby who does not sleep day or night!!!! we also have a 6yr old golden ret and a 16 week old puppy so pee everywhere as well so here goes a few tips
have seperate boxes for younger children with activities for them to do, like file folders, pens and paper, water jug in the sink (bit messy), fun with phonic dvd, magazines etc, ds loves playing with unifix cubes colour and counting i find that ds wants to do 'work' when dd1 is doing work.
let the younger children play with duplo, dolls house, car garage, etc
one positive thing about having them so young and close together is, once you have done english and maths, the rest of the subjetcs all the kids can do together, we do things like reading, giant map games are great, experiments, nature walks.
i am very lucky as my husband helps with the housework, and ironing does not get done it has to be teamwork or it does not work
have you looked at five in a row or ambleside on line, i have not used them but maybe worth a look.
hth mt3 x