Beth Mead's debut goal was an acrobatic finish, just seconds after she started as a substitute.
Sarina Wiegman, England manager, says Beth Mead "started shining", when she was substituted to score a hat trick in 14 minutes at Wembley Stadium.
Mead scored in the 74th minute, just seconds after coming on to give England the lead over a stubborn Northern Ireland team.
England won comfortably their World Cup qualifier with 4-0 victory over fellow sub Bethany England.
Wiegman stated, "Ofcourse she feels good. That we can see."
"I am so happy for her and the team to have scored three goals. Players feel at ease so they can shine. She was a shining star when she first came on, and did a great job.
"Today was a difficult game, but we were able to work together and feel good. We just want to keep moving forward."
Mead has been in great form for Arsenal and England, scoring four goals in her three previous internationals. Wiegman said that her performance against Northern Ireland was a sign of her confidence.
"She is in a good place right now and it's clear that she's a great footballer. Wiegman said that she feels great and has shown this on the pitch, as well as in training and with Arsenal.
"I'm going make an agreement that that we do this every game - we bring in a player and they score 3 times!" It's great!
It's what you need in order to reach a higher level of play and win matches. It doesn't really matter who scores. We just need to score.
Wiegman will be facing a selection headache Tuesday against Latvia, but the Dutchwoman insists that she is happy to have depth in her squad.
She said, "We brought in some new players to the pitch and they made an impact." "This team is diverse and we must pick and choose many of the players.
"I think I'm a bit lucky. They were ready to go in. This is what the team needs. They must be available for the replacements and that is exactly what they did.
"One of my proudest moments"
All four goals were scored at Wembley by substitutes
After England's players had been applauded for a lap in honour at full-time, Mead took photographs on the Wembley field.
Many fans stayed behind to shout her Name, while relatives waved from the high boxes in the stadium.
Mead said that even scoring a goal at Wembley was an incredible feeling. It's an honor to wear this shirt and score for my country. But to get a hat trick is something special and I'm happy to have helped the girls get three points today.
"[Wiegman] told me to get out there and enjoy it, make a difference, and I believe that I did. Sarina believes in each one of us.
It's definitely a career highlight for me. It's probably one of my proudest moments. I scored a hat trick at Wembley for my country.