In theory, that makes it possible to compare photos of her with painted portraits. However, based on some Googling on my part, it seems likely that most photographs of her were taken during the last half of her reign. I was able to find a few that provide comparisons with most of the paintings I selected.
As for the paintings, because they are of a monarch, they tend to be cautiously done, perhaps even a bit more so than commissioned portraits of others.
Victoria was about 35 years old when this was taken.
Painted around the time of her coronation.
Winterhalter was a go-to portrait artist for royalty and nobility.
This shows Victoria with Prince Albert who died 14 December of that year.
Winterhalter seems to have firmed up her chin for this official portrait.
Victoria was about 80 when this was painted.