According to Metal Underground website, the german/norwegian band Leave's Eyes will be mini-touring with Tarja in May. They'll do 11 concerts together, all of them inside Germany.

Here are the tour dates:

May 03 - Stuttgart, Germany - Longhorn
May 04 - Erlangen, Germany - E-Werk
May 06 - München, Germany - Backstage
May 07 - Karlsruhe, Germany - Festhalle Durlach
May 10 - Bonn, Germany - Brückenforum
May 11 - Osnabrück, Germany - Rosenhof
May 13 - Hamburg, Germany - Große Freiheit
May 16 - Leipzig, Germany - Haus Auensee
May 17 - Neu Isenburg, Germany - Hugenottenhalle
May 19 - Bochum, Germany - Matrix
May 20 - Hannover, Germany - Capitol

The same site, Metal Underground, says Tarja will take part in the German festival, Rockharz Open Air. The event will happen between July 7th and July 9th at Harz, Germany, and has the following line-up:

AMORPHIS
CALIBAN
EMIL BULLS
END OF GREEN
FEUERSCHWANZ
FREI.WILD
GRAND MAGUS
HACKNEYED
HAIL OF BULLETS
HAMMERFALL
HYPOCRISY
IN EXTREMO
LETZTE INSTANZ
ORDEN OGAN
PAUL DI'ANNO
POWERWOLF
SALTATIO MORTIS
SEPULTURA
STAHLMANN
TARJA
THE NEW BLACK
TURISAS
TÝR
U.D.O.