Mrs Biggs said students had never brought weapons to school in her time there, and she was "pleased to say" there had been a drop in stand downs and suspensions last year.
Some students had been disciplined for bringing marijuana to school.
The new guidelines reflected what was already being practised by her staff with search procedures, she said.
She expected her staff to treat students with respect when searching their property.
Mrs Biggs said most students who were being cyber bullied were willing to show teachers any images taken of them.
"For us it's about teaching kids how to respect each other ... if you've got a respectful culture in your school then kids will give you that material anyway and you can deal with it."
Secondary Principals' Association ex-president Patrick Walsh said education representatives were meeting with the Education Ministry this week to discuss how the search rules would affect electronic devices, which could be used for cyber bullying.
At present teachers could confiscate tablets or smartphones, but could not search the contents.
Schools had a small window of opportunity to delete malicious or intimate images of students, before images were uploaded to the internet by an offending student.
Mr Walsh was keen to see the ministry work with internet providers and internet safety body NetSafe to improve students' safety from cyber bullying.
Current association president Tom Parsons said although some principals would not be happy with the new search rules and guidelines, the legislation gave schools clarity on what they were legally permitted to do.
"The effectiveness of these [rules] will come out in the fullness of time."
Some principals had to search students on an almost daily basis, whereas others only needed to do so occasionally, so it was difficult to issue a "blanket guideline".
Knives were the most common weapon Kiwi students brought to school as an act of bravado or if they were being bullied.
"Kids mistakenly think that they're going to be better protected by carrying a knife."