Lewis said Caucus took rules seriously, particularly around confidentiality.
"If people don't abide by that confidentiality, then as a caucus we can't do our job properly, so it really is crucial to our policies and our job," she said.
Regarding whether Sharma would see further disciplinary action, or be expelled entirely from Parliament, Lewis said she saw no need for Labour to enact the so-called waka-jumping legislation to force Sharma out of Parliament entirely if he left the party.
"The Prime Minister has also said she didn't see the need for us to go down that path."
Sharma's accusations of bullying had been aimed at the office of whips, and former chief whip Kieran McAnulty.
Lewis said both McAnulty and the whips had been nothing but supportive of her whenever she reached out for assistance, such as when she had to organise her maternity leave.
"Any other time I needed to go to them with a question... they made us feel really welcome and really well supported."
She said she had not experienced any bullying in parliament, and her team of staff had not raised any concerns about bullying to her.
On the issue of communication with MPs and staff, she said there was always room for improvement.
"The last few days I've been doing some reflection on how I could potentially improve communication across my team... and there is always room for improvement."
She said that now the party had gone through the process of dealing with Sharma's claims, they can look at how to refine their communication further.
Sharma has said he wants an investigation into his allegations.
"When I tried to present the facts … the specifics, I was told I can't talk about it," he said on Tuesday.
Sharma said he will think about whether to stay on as an independent MP.
"It's not something I'm going to rush either way."
He would continue to push for an investigation, despite the PM saying she had seen no grounds for it
"It's not easy walking into a situation like this. But at the end of the day, I don't have anything to hide. I wanted to put my point forward."
Labour's Te Tai Hauārau MP Adrian Rurawhe chose not to comment on Sharma's expulsion given he was leaving caucus to take on the role of Parliamentary speaker.
However, Rurawhe said he had experienced no bullying during his time in Parliament.
"I think the relationships are a two-way street, so I've never experienced it in here, I can well imagine that in this kind of robust environment that could happen, but I certainly haven't experienced it," he said.
Incoming Labour list MP Soraya Peke-Mason who is based in Rangitīkei, would not comment on Sharma's expulsion.
She said as she is not yet a member of the Labour caucus, and had no involvement in the vote, she was not in a place to comment.
