Megan Jones and Sarah Bern admitted England have work to do despite the world champions starting their Women's Six Nations campaign with a convincing 33-12 win over Ireland.
In their first outing since beating Canada in September's World Cup final, two tries from Bern and one each for Amy Cockayne, Jess Breach and Ellie Kildunne ensured a 34th Test win in a row for England.
in front of a record Women's Six Nations crowd of 77,120 at Allianz Stadium, Jones accepted England were not at their best.
"I think there was always going to be nerves going into a big campaign off the back of an amazing World Cup," the England captain told the BBC.
"We wanted to play in front of big crowds and that is what we have today. We found our way and that is what a winning team does. I am sure we will brush up but I am really proud of the girls."
Jones was leading the side for the first time with World Cup-winning captain Zoe Stratford among four England players absent due to being pregnant with her first child.
She added: "I will probably sit and reflect [tonight]. Coming out of the tunnel was amazing, seeing everyone and singing the anthem."
There were just seven survivors from England's World Cup final win at a sold-out Twickenham last autumn and Bern acknowledged a new-look side was always unlikely to hit the ground running.
"We've got a new combination of players, and we've got a lot of youngsters in. We knew it wasn't going to be perfect and we were never expecting that," said Bern.
"There were some elements that we were really celebrating and there are some elements that we'll definitely reflect on. But the atmosphere in the stadium was just fantastic, and that always helps us get over the line."