Considering the last blood test revealed you had mild anaemia, your legs are swollen and I heard a heart murmur, I am recommending the following plan:

1.  Urgent please book an appointment for non-fasting blood test
You can drink coffee, tea or juice or you can eat before the blood test
These tests will check the level of your iron proteins and also if your heart has any problem pumping the blood for ferritin, protein electrophoresis, and BNP

2.  Please phone the surgery and request an appointment for ECG (electrocardiogram)

I am recommending this test to assess your heart activity
3.  I am referring you to have an echocardiography

An echocardiogram, or "echo", is a scan used to look at the heart and nearby blood vessels
The scan can give accurate pictures of the heart muscle, the heart chambers and structures within the heart such as the valves.
You can find useful information at this address:
https://patient.info/heart-health/echocardiogram

4.  Please increase the daily dose of your FUROSEMIDE. 
Take another tablet of 20 mg altogether with your regular daily morning tablets of furosemide.  Recently took her morning dose of 40 mg furosemide.
This is the water tablet, which will take out water from your body so that your heart will have an easier job to pump your blood. 
As your legs are swollen this tablet is likely to reduce their swollen mass. 
If you have any side effects, please stop the new prescription tablets and continue with your routine tablet of 20 mg furosemide each morning.  If you cannot increase daily dose of furosemide, please contact the surgery and speak to your GP.
The side effects often reported are: Blurred vision Confusion Dizziness Drowsiness Dry mouth Headache Hearing loss.
If you have no side effects from this medication, please continue the increased dose of furosemide for 4 weeks.
5. If you continue to take furosemide 40 mg daily, please have non-fasting blood test in 2 weeks since you increase the furosemide dose. This blood test is for kidneys function (U&E) and is needed to check if your body tolerates well this medication.
If you do not hear from GP regarding the results, this is because your tests are good and you should continue daily dose of furosemide up to 4 weeks.

6. If you continue to take furosemide 40 mg daily, please check your blood pressure (BP) twice a day, ideally once in the morning and once in the evening
When checking your BP, sit down quietly for about 5 minutes with your back supported by backrest and legs uncrossed
Each time you do this, you should take two readings, 1 minute apart. You should continue to measure your BP twice daily for at least 4 days and ideally for 7 days
See the following link on how to do home BP monitoring
https://drive.google.com/file/d/1eBN9QSwlJ8xiJu7N-sl1IlD-605jNHs3/view?usp=share_link
 https://bihsoc.org/wp-content/uploads/2017/09/Home_blood_pressure_diary.pdf
I strongly recommend you record your pulse the same time you record your BP
Please send your BP diary to the surgery for a GP to see it
7.  Urgent, bring to the surgery a stool sample to be sent to laboratory - test FIT (Faecal Immunochemical Test)
This is a stool test designed to identify minute amounts of blood in faeces. 

I am recommending this test as an investigation of your anaemia.

Many bowel abnormalities which may develop into a more serious disease over time, are more likely to bleed than normal tissue. So, if there is blood in the stool this can indicate the presence of abnormalities in the bowel. Patients with a positive FIT result are referred for further investigation by colonoscopy.
Please come to the surgery and request a special kit for stool test -FIT test
8.  Urgent, please bring to the surgery a stool sample to be sent to laboratory - test FAECAL CALPROTECTIN
This is to test if there is any inflammation in your bowel. An inflamed bowel can make you to feel bloated, feel nauseas, and have diarrhoea or some other abdomen symptoms and can cause the iron level to be low that may lead to anaemia

I am recommending this test as an investigation of your anaemia.

Please come to the surgery and request a stool pot

9.  If the test or investigation(s) result(s) is/are good or satisfactory, you will not hear anything from GP surgery.
If you do not hear anything from GP regarding the test(s) results you should book a face-to-face GP consultation.  For follow-up in 3 weeks