Queen Louise was present at both Louise Fife's wedding in 1889 and George and Mary's wedding in 1893 in England. The painting by Tuxen (in the Royal Collection) shows her sitting next to Queen Victoria. So they did meat (at least during these days) and I cannot imagine they haven't had a conversation (as grandparents of Louise and George). The famous photograph of the three generations: Queen Louise, Queen Alexandra and Louise Fife was taken at the occasion of the wedding of prince George and princess Mary in 1893.
I never read anything about Queen Victoria visiting Denmark and definitely not during the famous ''family reunions''. Didn't she hate these gatherings just like the Rumpenheim ones? I thought she saw these gatherings as a place for gossip and scheming and followed it with much suspicion. I know Queen Mary's mother Mary Adelaide was present at these Rumpenheim gatherings (so was her sister Augusta) and wasn't Queen Mary there too as a little girl? They probably have met Queen Louise during these family gatherings, but Queen Victoria never attended these gatherings either (?). Offcourse these Rumpenheim gatherings were very anti-Prussian in the first place - so it must have been hard if she did.