Can you volunteer at a paediatric or children's based organisation to show an ongoing interest in that area?
I don't know what sorts of opportunities are available where you live but perhaps look into paediatric hospices, respite centres or schools
for children with disabilities, the volunteer program at your local paediatric hospital, organisations that run camps for children with particular health problems (e.g. the two children's hospices in my state run a camp once per year for children who've had brain injuries, we have a national organisation that runs regular camps for children with cancer and other organisations are taking off running camps for kids with everything from heart disease to intellectual disabilities)...
Those are just a few I guess.
I'm a new grad this year (in Australia). Through my degree I worked at a paediatric hospice for a year, a rehab/respite hospital for children with severe mental and physical disabilities for two years and these put me in a good position to gain an undergraduate nurse position at one of the major children's hospitals the year before I graduated. I also volunteered on a regular basis at a school for children with severe disabilities (I still do). I think these things, in combination with a strong commitment to my academic work and involvement in university and nursing related extracurricular activities (eg. I'm a member of the national nursing association's faculty for early career nurses) put me in a good position to be offered a new grad job in a tertiary paediatric hospital. We spend six months in two departments at new grads and I'm about to go to the PICU for my second rotation.