will writing is it required in my scenario?

Robin9

Please, please go to a solicitor  - your family is too important.

Others have mentioned the scenario of your joint deaths and who would look after your children  now under 8.  - your parents, your friends.  What if they were teenagers ? Perhaps your parents might not cope ?

getmore4less

You can deal with guardian appointment outside a will.

Often better as easily updated

Guardian appointment only comes into effect when the last person with parental responsibility dies and it is theirs that applies.