One on one, meaning me and just one child? Honestly, not that much for the older two. I'm a SAHM and spend lots of one on one time with my 3 year old while her brother and sister are in school. I spend a lot of time with the bigger kids too, but generally I have all three kids together at that point.
luckily I still get to have some awesome one on one times with my daughtes. Last year Kitten and i drove up to Mi and this year it was Pumpkin and me. GRandkids came too but the quality time with my daughters was priceless