Note: Apologies, but there is no way to ask this question without revealing major spoilers.
In the Wheel of Time series, it's revealed that Thom Merrilin was once the lover of Morgase, queen of Andor. By the time of Book 4 (The Shadow Rising), Elayne Trakand starts to remember that Thom was present for the first several years of her life. Afterwards, their relationship is often described as that of a father and daughter, with Thom taking great pride in her accomplishments & skill. It is also mentioned that Morgase's marriage to Tarangail Damondred - supposedly the father of both Gawyn and Elayne - was loveless and somewhat strained. It is never said exactly when, however, Morgase's affair with Thom began. And lastly, Elayne is never described as having any of her father's features (unlike Gawyn), but only Morgase's. This all leads to the question...
Is there any indication in the Wheel of Time series that Thom Merrilin could be the biological father of Elayne Trakand, or was he simply Morgase's lover for a time?