WWYD- 3 part time jobs

[pugsandseals]

I am in a confused place right now, doing the same job for 3 different companies. Company 1, been there years on a contract but have gradually reduced from 50% to 30%. They are struggling to find enough work for everyone & I am currently spending about 2 hours per week twiddling thumbs.
Company 2, started a couple of months ago 20% hourly paid maternity cover. Really like it, closer to home & the potential for them to want to keep me after maternity cover. Not sure how much security in it though.
Company 3, Started a couple of months ago on a 20% contract but already found me some cover work (another 10%) & potential to grow. They are struggling to cover a long term sickness with other hourly paids, but are quite a new business. I have been asked to find out what my notice period is from company 1! Would be a hard but rewarding job right on my doorstep.
I need 60-75% stable pay. Contracts are preferable but I like job 2 almost as much as job 3.
Question is, what would you do if (& I suspect when) job 3 offer more on contract? Drop job 2 or reduce/drop job 1? I really need security but want to be able to enjoy my work as well!
Confused!

[pugsandseals]

Any thoughts would help!