Yes, rincon is our favourite.

Memories there with whispers Sinatra's etc.in lg Asturias do great Chateaubriand. Charlie's is excellent. Ibericos good. La bodegitta good jardin del sol will retry on return. Tipsy terrace great for lunches.flr del drago casa Pepe's tapas y tapas all great in playa de arena and Domingo's.enjoy.

You have to pay to use oasis but the other lido is free if you're staying in Poblado. Both have bars and restaurants.
Rincon de antonio closes a lot over the Christmas period but you are spoilt for choice really as far as restaurants go in LG. We have never needed to book in either el pescador or la boduegita. Both are good.

Last Christmas was the worst weather-wise I've ever experienced in LG, it was windy and only about 18 in shade most days. We kept getting the bus up to Puerto de la Cruz where it wasn't windy and was about 24! Most previous years though have been mid 20's and can sit out until about 10pm as it stays around 20 degrees all evening. Whatever, it'll be better than UK!

It's lovely to see the poinsettias everywhere.

Poblado is at the edge of the marina, but it has a very steep hill to get into the main area.  The Oasis is up part of the hill and around the corner and is fabulous.  Its been recently refurbished.  Great for children and adults alike.  The food is really good and reasonably priced so you can stay there all day.  Toilet and shower facilities are excellent.  You will need to research which restaurant you eat at for Christmas and will need to book as they get busy.  I have not seen Santa around for many years.  If you are still there for January 5th there is the Three Kings celebration where children receive gifts (donated by you) from the Kings in the evening with a parade in the streets.  There is a bus service you can use to get in and out but the bus stop is a good walk from Poblado for your Mum.  Taxis are quite reasonable as an alternative option.  We have had years when the weather has been really good about 22 degrees and able to sunbathe. Last December/January was awful and the first time ever I have gone out with a jacket on in the daytime.  Have a great time when you get there.

Have you checked the weather in December? not sure how much pool time you'll be having unless your very hardy or you find a pool heated by something other than the sun, personally I love the weather in December/January and over the years we've had some beautiful weather there at that time of the year but we've also had some cooler days, the sun is very low in the sky, it comes up late and it gets dark by 5:30/6:00, We still only need summery clothes but more cotton trousers and t-shirts than shorts and vests. In the evenings you need something slightly warmer (a jumper or light jacket) and you will find you are eating inside in restaurants - although its still mild enough for the to have the doors and windows wide open.