Driving without due care and attention - mitigating circumstances

[loopyloo111]

I am pleady guilty guilty by post to the above offence, I pulled onto a dual carriageway from a junction without giving way forcing two cars to swerve into lane 2, no accident happened but a police car saw it happen.
I have never driven on the road before and have only joined a dual carriageway through a slip/filter road, so did not realise i was meant to stop.
I have noted my lack of experience in driving on such roads.
Is it worth mentioning that my 18month old daughter was sat next to me which can be distracting, but my car is not suitable for a baby seat to go in the back, I have learnt from this I really need to try and block her out whilst I'm driving.
Should I also mention how serious I realise it is and could have been?

[loopyloo111]

"Offer only your lack of experience and general contrition, you'll get a lenient sentance."

Thanks for the advice think this is what I'll do