user11442: I gave someone 3 months to become as good a chess player as I am. She was just a beginner and I'm a slightly below average player (around 1500 elo).
To see if she managed to do this, I figured we should play a chess match consisting of multiple games. 
But what is a reasonable or standard amount of games to play in a chess match (or a 2 player tournament, if you will)?

user10233: Play 6 games at G15 or G30. record all the games so you can review them afterwards. That will give you just enough games to gage her play.

user7297: The amount of games in a match is usually* even, to guarantee an equal balance between White and Black. 2 game (mini)-matches are rare, except in knock-out tournaments like the Chess World Cup. More games will produce a more reliable result, so you should play as many games as you have time for, but 4 games should already give a good indication about who's the better player. With some mathematics and the expected performance formula you can calculate the odds of losing an X-game match to a player who is Y ELO points better/worse than you.
*: The only exception is an Armageddon game which can be used after a match which ended in a draw (i.e. the same score for both players).

11442: <p>I gave someone 3 months to become as good a chess player as I am. She was just a beginner and I'm a slightly below average player (around 1500 elo).</p>

<p>To see if she managed to do this, I figured we should play a chess match consisting of multiple games. </p>

<p>But what is a reasonable or standard amount of games to play in a chess match (or a 2 player tournament, if you will)?</p>
 10233: <p>Play 6 games at G15 or G30. record all the games so you can review them afterwards. That will give you just enough games to gage her play.</p>
 7297: <p>The amount of games in a match is usually* even, to guarantee an equal balance between White and Black. 2 game (mini)-matches are rare, except in knock-out tournaments like the <a href="https://en.wikipedia.org/wiki/Chess_World_Cup_2015" rel="nofollow">Chess World Cup</a>. More games will produce a more reliable result, so you should play as many games as you have time for, but 4 games should already give a good indication about who's the better player. With some mathematics and the <a href="https://en.wikipedia.org/wiki/Elo_rating_system#Mathematical_details" rel="nofollow">expected performance formula</a> you can calculate the odds of losing an X-game match to a player who is Y ELO points better/worse than you.</p>

<p>*<sub>: The only exception is an <a href="https://en.wikipedia.org/wiki/Fast_chess#Armageddon" rel="nofollow">Armageddon game</a> which can be used after a match which ended in a draw (i.e. the same score for both players).</sub></p>
