Surprisingly, this is a question that comes up somewhat frequently, either in family situations or in the workplace (as in, Is X plotting to get my job?). These kinds of charts are interesting because the first thing that has to be figured out is which house represents the sister-in-law? 

In this case, it’s easy: as the husband is represented by the 7th house, his sister will be symbolized by the third house (siblings) from the 7th, which is the 9th holding Gemini. So we look for Mercury in the chart and what do we find? Mercury is in Aries, retrograde, and exactly opposed to the Ascendant, representing my client. Based on the state of Mercury, an easy description of the sister-in-law would be verbally aggressive, destructive and opposed to her best interests or point-of-view. In a word, nasty.

But as I wrote in my answer, the real problem here is less between my client and her sister-in-law and more between my client and her husband. He is symbolized by Mars – in Aries – so he feels very strong, very powerful. My client is symbolized by Venus – just entering Aries – where she feels potentially weak, impulsive, frustrated and working against herself. Also with Venus in the 6th house – of slavery – we get a sense of her being under the yoke, so to speak. Finally, her Venus is placed in his 12th house, so he potentially sees her as opposed to her in some way.

In horary, we also look at the Moon as symbolizing the client and once again, the Moon in this chart is weak. It has no strength in Sagittarius, it is void-of-course (meaning that it makes no aspects to any other planet) and it is moving quickly, meaning that events are probably moving quickly.

Finally, let’s not overlook Saturn on my client’s Ascendant. While Saturn has dignity in Libra, it is also retrograde – moving backwards and directly opposed to Mercury (the sister-in-law) – and rules her husband’s 10th house of profession. (Is this a family business situation that the client is involved in?)

We’ll get to that answer in a moment, but before I do let’s see if there is a resolution in sight. As Venus (the client) has just entered Aries (where it is in the power of the husband), it’s unlikely this is going to resolve quickly. In addition, the Moon will next enter Capricorn, where it will be in worse shape than its current state. With the Sun (co-ruler of the client’s husband) entering Taurus, I suggested that she worry less about the sister-in-law and work to restore harmony with her partner, because the fact is the dominant planet of this chart is Mars (the husband).

What follows is an edited version of my client’s reponse:

“Chris, thanks for the insight. This is indeed a family business which I have just become (reluctantly) a part of. I don’t think anyone is comfortable so far, particularly his sister, and the situation has brought HUGE tensions between my husband and I. My biggest concern is that this does not have a quick resolution but I suppose that’s more a reflection of my impatience and stress than a realistic expectation.”