Soil holding water at roots

I've had my girl since July, she is 12, it's been mind blowing learning how to look after her but I feel I'm getting there, had aphids a couple of times but sorted that but always had an issue with watering, done what it says and end up overwatering, I've now been aerating the soil as the roots and lower part of the part always seem wet, aerating by loosening the soil, however, I've decreased the watering and she seems to be coming really good (including some extra lighting due to winter months), but a few leaves are turning black/brown around the edges, I've just checked on her and put a chopstick through the bottom holes of the pot and the soil is still quite wet so my question is do I keep aerating until the spring and then look at repotting, im just curious that the soil isn't that good and is not allowing proper drainage, I haven't changed or reported since having her, can I ask for some ideas? Some pics attached, advice would be greatly appreciated thanks

That is a chinese elm. It will not fare well kept in living room conditions. It needs winter dormancy. Try to cool it down to 5-10 degrees from now until spring. When it is safe above 5 degrees outside, bring it outside gradually letting it get used to full sun. Once outside leave it there, the only thing you need to be worried about is prolonged times of deep frost. Then it is good to protect it in unheated greenhouse, cold frame or shed.

Good luck.

Thank you so much for your reply, I've actually kept her in the kitchen which is a lot cooler than the rest of the house but will do as you suggest as soon as the weather allows

Fyi: 5c equals 41f and 10c equals 50f. Anything above that will not give the tree a proper dormancy. The tree needs at least 6 weeks of dormancy. What is the temperature in your kitchen?

I think my kitchen is more than that, but will find somewhere that is between 5 and 10c, sorry if I sound so uneducated, with regards to dormancy amd I right that she still needs 12 hrs or sunlight and feeding once a.month? Thank you so much again

Sunlight is not at all that important during dormancy. Absolutelly no fertilizer during this period.