I will give only loose direction to keep things natural. If you feel uncomfortable, you will look uncomfortable.
I have kids, they all have their off days, some rarely have an 'on' day! Don't worry, I've seen the 'I'm not going to smile' face before!
Want kids to run around more than stand still, no problem, I can cover that too.
I've never known any parent to say 'I wish we took fewer special photographs of the kids when they were growing up'. It just doesn't happen. One minute they are are all cute with teeth slightly too large for their faces and the next you only see them when they need to borrow the car. Families grow up fast and capturing your young family in a beautiful family photo is something parents very rarely regret.
After photographing babies and families in the studio for years I found I preferred the look and feel of the photographs I was taking of my own family outdoors. It dawned on me that this is relatively rare as a service, true family photographs but captured professionally and with all family members in shot.
I can capture your family as a group or individually, staged or running around at the park having fun or a combination. Naturally I have more control over a staged portrait, but in good light (particularly in the Golden hour) its possible to get some beautiful natural portraits too.
A typical family shoot lasts from 1 to 2 hours depending on the age and patience of your little ones which is long enough to try out a few different scenarios and ideas. Most of my shoots take place in local parks and woodland. You pay a £30 session fee at the start of the shoot and a week or two after the event you are given a link to a library of image previews. If you wish to, you can then purchase a download of all the high resolution images from the shoot for £120 and you can expect to find 20 to 30 images in the download link.