Im exactly the same, and the only thing we do is when Jess is napping then we get on the floor with Isla and either rough play, or read her 'words' book, or play feeding 'babies'......
But thats only when Jess is napping, the rest of time she entertains herself too Amanda.
I find it more the other way though....poor Jess gets ignored a lot, I feed her and then put her down and carry on with jobs, and then shes sleeping!
Youre not a bad mum love, just a normal one! xxx