An ever-present during their recent unbeaten run, Findlay netted for the first time this season to set United on their way to an impressive victory at the Lancashire FA County Ground.
The young Scot spent much of the evening up against experienced frontman Anthony Stokes - with whom he played at Celtic prior to his move to Tyneside.
Stokes was not the only seasoned campaigner on display for the home side, with veteran defender Wes Brown - formerly of Manchester United and Sunderland - also completing 90 minutes for Rovers' second-string.
Beardsley felt that Findlay used his own experience to full effect, however, the 21-year-old now firmly established at the heart of the young Magpies' backline.
"To be fair to him, there were a couple of games where he was out of the team - when, without being negative, we had more players available. There are times when you do lose your place, and that's the real world. You have to get back in as soon as you can, and he has been one of the brighter figures during the run we have had," he told nufc.co.uk.
"Last week, West Brom came to our place, and they were up against (Achraf) Lazaar, (Massadio) Haidara and Daryl Murphy. It was a bit like that for us tonight, I guess. I thought the younger ones at the back - Gippa (Liam Gibson) and Cal (Callum Williams) - coped really well, and we had a bit of experience in the middle with Curtis (Good) and Stuart. Stuart knows (Stokes) from Celtic, and he knows that to expect. He knows - with all due respect - that he is not going to run away from people, so that gives you a bit of an advantage."
United were able to secure a fourth win in five outings without the services of leading goalscorer Sean Longstaff, who sat out the trip to Lancashire with a hand injury.
Beardsley admitted Longstaff's presence was missed during an edgy first-half, but paid tribute to his side's showing in the second.
"Sean was a miss, certainly in the first-half, but to be fair, the players found a way to win tonight," he said. "That's what you have to do. Sometimes in football, you are going to be without your best players.
"It was - literally - a game of two halves. Blackburn were definitely the better team in the first-half. They put us under a lot of pressure early on, and were probably quicker and sharper to the ball. We put a couple of things right at half time, and I think we've deservedly won in the end."