In her horary book, Barbara Watters mentions that, when the Moon is besieged between two malefics (that is, it has just conjuncted one and is moving to conjunction with the other without making any other aspects in-between), no positive outcome is possible. I'm looking at a lost-article chart where, at the time the question was asked, the Moon in the turned 2nd House (my wife is the owner of the item) had formed a conjunction with Mars around 20 degrees ago and would conjunct Saturn in another 10 degrees. No intervening aspects occur from the time the question was asked up to the second conjunction. However, the Moon was only a few minutes of arc past the square to Venus (significator of the misplaced piece of jewelry) when the question was asked. Watters says that past aspects show events that occurred before the question was asked, according to the time-frame - hours, days, weeks, months, years or indefinite - shown by the nature of the signs and houses involved. Although the Venus square was separating but still partile and very close to perfection, it was still in the past. Watters doesn't say that the last conjunction of the Moon to a malefic had to be the last aspect formed by the Moon when the chart was cast, just that there can be no further aspects from the time of the question to the next conjunction. Any opinions on whether this condition would invalidate besiegement in this case? My gut feeling is that the item is gone for good this time (it's the second time my wife lost it).
Lilly defines Separation as commencing when the faster planet is six minutes of arc ahead of the slower one. Separation is not complete till the planets have reached the limit of their moeities. For example Jupiter and Saturn would need to move 9 degrees apart before they are totally separated.
Lilly is a little vague on beseigement. His example has Saturn at 15 Aries, Venus at 13 Aries and Mars at 10 Aries. In this case Venus has not separated from Saturn and is applying to Mars. The whole range is covered by their two moeities. Abu Ma'shar seems better here. He identifies two forms.
The first is where all three are placed in one sign (as above). The second is when a malefic
or its rays are in the second sign from a planet and the other malefic
or its rays are in the twelfth sign from it. Note that aspects count in the second situation. In the first the planet and malefics must all be in the same sign.
Abu Ma'shar also allows an escape. If either of the benefics or the Sun aspect the besieged planet within 7 degrees, then the beseigement is lifted. This applies to both forms.
Beseigement, strictly speaking means that the Moon is somewhere between the two malefics...that is they will be consecutive conjunctions.
Now from your description:
Watters is correct if the Moon is beseiged by the malefics then its highly unlikely that good will come of the matter.
The span between the two malefics is around 30 degrees, so it's unlikely that they meet Abu Ma'shar's definition of condition 1, that is all three planets must be in the same sign.
Even if they do, the aspect from Venus raises the siege.
That still doesn't mean the jewelry is recoverable as the 'few minutes' past the square could mean that separation has set in. I'm using the Moon as a co-signficator for you/your wife there. . Unless there's something else in the chart which suggests recovery then you might still be in the same situation.
However it's worth checking the chart again, just to make sure.