The Ullevaal arena is sold out for Saturday's clash between Spanish giants Barcelona and French juggernaut OL Lyonnes, but Bonmati told Catalan media outlet RAC1 that the 28,000-capacity venue represented a retrograde step for women's football.
"Norway is a fantastic country, but the conditions are different. We come from filling large stadiums, and going to a smaller field is a step back," Bonmati said.
Mjelde hit back by pointing to last year's final, where Arsenal beat Barcelona 1-0 in front of 38,356 fans in Lisbon's 52,095-capacity Estadio Jose Alvalade.
"A full Ullevaal is cooler than a half-full stadium somewhere else - if I'm not mistaken, it wasn't a full stadium for the final last year, even though it was in a bigger stadium," Mjelde told Reuters in the sunshine outside the downtown hotel that European governing body UEFA is using as its base for the final.
"Of course, you want to play in the biggest stadiums, but not all countries have them. Barcelona are very lucky and privileged in Spain, and it is probably the team in the world that attracts the biggest audience, but it's not like that everywhere, and I think that, if you can show football in several different countries, it will be much more attractive."
Barcelona boasted a crowd of more than 60,000 at their Camp Nou stadium for a 6-0 thrashing of bitter rivals Real Madrid in April, but averaged just over 6000 fans for their home games this past season.
Mjelde, 36 and back playing in Norway after spells in Germany and England, emphasised her country's pedigree as one of only five teams to win the women's World Cup as further justification for having the women's final in Oslo.
Leading the way
"Norway was the world leader for a while, and we want to get back there," she said.
Though disappointed by the criticism, there was no anger towards Bonmati from Mjelde, who reached the 2021 Champions League final with Chelsea, but missed the 4-0 defeat by Barcelona through injury.
"I think if she had discussed this with the other Norwegian girls (at Barcelona, Caroline Graham Hansen and Martine Fenger), they would have said something completely different," Mjelde said with a smile.
"We are, of course, a bit biased in this, and it's a bit subjective, but I think Aitana will experience a fantastic atmosphere. The weather is nice, and she gets to be in Norway, which is a really nice country, so I think she will find it cool anyway."