[Dates?] Ashby-de-la-Zouch, Leicestershire, England (Grass)
FI: Winifred Longhurst d. Elsie Lane 6-3, 6-4
The list of 1906 tournament dates in LTAB shows "Ashby (Leicester Championships)" on July 9, 10, 11. That seems to be in tune with the results published in the August 1 issue and there described as "recent".
MX: Toni Popp (Ger)*/Laurie Doherty (GB) d. Toupie Lowther (GB)/Arthur Gore (GB) 6-0 6-2
LTAB confirms these dates; in the April 4, 1906 issue, p.524 it mentions "The open events of the Nice Lawn Tennis Club's twelfth annual lawn tennis tournament were brought to a successful conclusion on the 19th ult. by the victory of ...." and earlier tournament adverts mention March 12 as the tournament start date.
We also had a score (source?) indicating the mixed winner was Countess Clara von der Schulenburg, Toni Popp's sister. Later versions of tennis annuals also indicate Schulenburg as the winner. Could she have been using her sister's name as a pseudonym?
March 5-9, Riviera Championships, Mentone, France (Clay)
March 12-19, South of France Championships, Nice, France (Clay)
In Mixed, Alan Little has these winners: Clara von der Schulenburg (Ger)/Laurie Doherty (GB)