Will have a go at the chart. Will be looking at the 8th house mainly as the house of surgery, and the 4th house from it.
Have not attempted many return charts and when doing so ..very briefly.
Applying basic events/activities appointed to the houses and signs/planets to possibly reflect on a good outcome for the surgery.
The first considerations about general health I see in the natal chart is the protective alliance of Jupiter moving by progressions to make a sextile with Saturn. Jupiter gives stamina, and even though in Capricorn - a place of its fall, the sextile Jupiter makes with Saturn the lord or ambassador of Capricorn/on your Mum's 6th house makes some statement about destiny (Capricorn is natural ruler of destiny 10th and is the Surgery outcome being 4th from the 8th/house of surgery/or surgeon) Jupiter sextile Saturn mitigates the harsh effect of his depositor Saturn. Thinkng he is saying I give you opportunity of health by being placed here.
Moon in the lunar chart squares (obstacle) with Mars-he moving out of the sign Gemini. Thinking the surgeons hands (natural Mars of 8th/Scorpio/surgeon-dignified in Scorpio in the natal chart-good ref. here as the way the incision/surgery will be effected?) Benign Venus is almost in the same position with Hershel in the transits, (significant of the near association values these two have in the natal chart.) Venus rules the flesh, next to transiting Uranus is the necessary incision point with transiting Mars natural lord of Aries (trine) Hershel/soon Venus in Taurus where your Mother's natural co/lord of Capricorn on the 6th house of health, good omens. (Transiting Venus 'trying' to accomplish the trine with transiting Mars, protecting softening his interests, activities as she approaches him, shining her light upon the surgeons hands.)
Transiting N.N. moving back into the 1st house to help in the healing process, strengthening her heart in Leo, making the grand trine with Hershel/Venus and Saturn all in fire signs significant of an undaunting spirit that will not give sway to defered value systems and demonstrative of optimisim to asuage your doubts.
Moon has passed making the trine to Assilli, and as the lunar pl. of the Natal Moon again seperates herself of depressive natal Saturn in the 9th, (thoughts) She squares transiting Saturn lord of Capricorn of the natal 6th house in Sagittarius, so there is some anxiousness there, but expected of someone in later years of life.
The transiting Pluto/Capricorn conjunction where natal Jupiter resides in the 6th is protective.
Where is the surgery being performed on your Mother's person, may I ask? Mercury as natural lord or host to the 6th house recieves a square from transiting Mercury, and as he author's 6th house concerns, might speak of the throat area, also consider Aquarius/Uranus/Saturn afflictions with Capricorn, Venus playing an important part in the diagnosis, women's afflictions-polupus areas being removed, overies, the skin? Transiting Venus has recently opposed natal Jupiter's position near the 4th, a culmination of events to these areas of concern. She being in detriment is not able to release herself from its deminished effect of her energies? The area's to be served are hidden deep? Am concerned of arthritic or leg ailments, tendons cartilage, Saturn rules the spine, back?
There are so many protecting energies surrounding the 6th house lords with 1st house natural hosts indicating dignified actions of Mars, Sun (strength) that I don't see any complications accept for the necessary healing process, which might accompany the expected discomfort, transiting Cheron in Pisces 9th house understands the doctor's advice with acceptance.
Hope you are assured of the surgery's success, all in all there is some discomforture, but it is to be expected as said above.
Wishing your Mother healing, and ease after the surgery.
Take care
All the best
Vyri